A garage-building programme for the city of Vienna and resulting air quality. Related health aspects

Energy Technology Data Exchange (ETDEWEB)

Tvrdy, C; Walter, R [Inst. of Environmental Medicine of the City Council of Vienna (Austria)

1996-12-31

Urban traffic influences air quality in cities considerably. This is particularly true for the medieval parts of the big European cities, which have not been designed for today s heavy traffic. A problem closely associated with city traffic, is the lack of parking lots, particularly for residents. In Vienna, the parking problem is tackled by the building of underground car parks. In the next years more than 50 large garages (>100 sites) are being planned. The main goal is the clearing of the beautiful old places and streets of Vienna from the bulk of parking vehicles and supplying the citizens with parking spaces in the neighbourhood. According to a recent decision of the City Council of Vienna the construction of `large garages` (>100 parking spaces) requires an official approval by various local authorities. Among them are those responsible for town design and architecture, for fire precaution and fire fighting, for city traffic, for planning and building and for environmental health. In this context the Institute of Environmental Medicine of the City Council of Vienna faced the task of establishing criteria for a health risk assessment linked with `large garages`. Health-risks may be caused by air pollution and noise. This presentation deals with the air pollution problem. Air pollution problems may occur due to traffic in and out of the garage, by insufficient ventilation systems and by construction failures. In the garage programme the health officers have to bring evidence that residents of the houses with underground car parks and residents in the close neighbourhood are not exposed to any health risk due to air pollution

Identity verification using computer vision for automatic garage door opening

NARCIS (Netherlands)

Wijnhoven, R.G.J.; With, de P.H.N.

2011-01-01

We present a novel system for automatic identification of vehicles as part of an intelligent access control system for a garage entrance. Using a camera in the door, cars are detected and matched to the database of authenticated cars. Once a car is detected, License Plate Recognition (LPR) is

Worksite environment physical activity and healthy food choices: measurement of the worksite food and physical activity environment at four metropolitan bus garages

Directory of Open Access Journals (Sweden)

Gerlach Anne F

2007-05-01

Full Text Available Abstract Background The present research describes a measure of the worksite environment for food, physical activity and weight management. The worksite environment measure (WEM instrument was developed for the Route H Study, a worksite environmental intervention for weight gain prevention in four metro transit bus garages in Minneapolis-St. Paul. Methods Two trained raters visited each of the four bus garages and independently completed the WEM. Food, physical activity and weight management-related items were observed and recorded on a structured form. Inter-rater reliability was computed at the item level using a simple percentage agreement. Results The WEM showed high inter-rater reliability for the number and presence of food-related items. All garages had vending machines, microwaves and refrigerators. Assessment of the physical activity environment yielded similar reliability for the number and presence/absence of fitness items. Each garage had a fitness room (average of 4.3 items of fitness equipment. All garages had at least one stationary bike and treadmill. Three garages had at least one weighing scale available. There were no designated walking areas inside or outside. There were on average Conclusion The WEM is a reliable measure of the worksite nutrition, physical activity, and weight management environment that can be used to assess changes in the work environment.

Removal of oil and grease from automobile garage wastewater using electrocoagulation

Science.gov (United States)

Manilal, A. M.; Harinarayanan Nampoothiri, M. G.; Soloman, P. A.

2017-06-01

Wastewater from automobile garages and workshops is an important contributor to the water pollution. Oil and grease is one of the major content of wastewater from vehicle garages. Wastewater from a public transport depot at Thrissur district in Kerala, India was collected for the study. A batch reactor has been devised to assess the efficacy of electrocoagulation in removing oil and grease from the wastewater. Aluminium and iron were tested as the anode material with stainless steel as cathode. Experiments were conducted to investigate the effect of various operating parameters such as current density, pH, time and salt concentration on oil and grease removal. The results shown that aluminium is superior to iron in removing the oil and grease from the wastewater. The reactor with aluminium as anode was able to remove 90.8 % of the oil and grease at a current density of 0.6 A/dm2 in 15 minutes. The calculated specific energy consumption is also less for aluminium in comparison with iron.

Occupational lead exposure among automotive garage workers – a case study for Jimma town, Ethiopia

Directory of Open Access Journals (Sweden)

Adela Yalemsew

2012-07-01

Full Text Available Abstract Background In Ethiopia, although there are numerous small-scale and medium industries which use lead-based raw materials that may pose health risks to workers, there are no workplace regulations for lead exposure. Moreover, there are no studies carried out on the blood lead levels (BLLs of workers or on the contribution of common workplace practices to lead poisoning. Method A cross-sectional study on the BLLs of 45 automotive garage workers and 40 non-garage workers was carried out in the town of Jimma, Ethiopia. In addition to BLL analysis, data on some risk factors such as smoking, and chewing ‘khat’ (the leaves of Catha adulis were gathered through structured questionnaires and interviews and data analysis was performed using SPSS (version 16. The t-test was used to compare mean BLLs of study groups. The analysis of variance (ANOVA, Kruskal-Wallis, Pearson chi-square and odds ratio tests were used to investigate the associations between specific job type, smoking and/or ‘khat’ chewing, service years and occurrence of non-specific symptoms with BLLs. Results The mean BLL of the automotive-garage workers was found to be significantly greater than that of the controls. The BLLs of all the lead-exposed individuals were found to be over 10 μg/dL, and 53% of them had BLLs ranging 12 – 20 μg/dL, with the remaining 47% having over 20 μg/dL. The BLL of the workers increased with the duration of working in an automotive garage. Individuals involved in manual car painting comprise a larger percentage (58% of those with the highest BLLs (≥ 20 μg/dL. Lead accumulation in individuals who chew ‘khat’ in the work place was found to be faster than in those who are not used to chewing ‘khat’. ‘Khat’ is an evergreen shrub native to tropical East Africa, with dark green opposite leaves which are chewed when fresh for their stimulating effects. Conclusion The findings of the study have clearly demonstrated that the

Constrained capacity management and cost minimisation of EV-charging in a parking garage

NARCIS (Netherlands)

Kamphuis, I.G.; Macdougall, P.; Veen, W. van der; Bakker, E.; Velde, J. van de

2013-01-01

Apart from the optimal real-time electricity price to buy the electricity, the optimal, time dependent, capacity contracted with the DSO is of crucial importance for concerted charging of electric vehicles in a parking garage. The battery management system, on its turn, imposes constraints on the

A BLE-Based Pedestrian Navigation System for Car Searching in Indoor Parking Garages.

Science.gov (United States)

Wang, Sheng-Shih

2018-05-05

The continuous global increase in the number of cars has led to an increase in parking issues, particularly with respect to the search for available parking spaces and finding cars. In this paper, we propose a navigation system for car owners to find their cars in indoor parking garages. The proposed system comprises a car-searching mobile app and a positioning-assisting subsystem. The app guides car owners to their cars based on a “turn-by-turn” navigation strategy, and has the ability to correct the user’s heading orientation. The subsystem uses beacon technology for indoor positioning, supporting self-guidance of the car-searching mobile app. This study also designed a local coordinate system to support the identification of the locations of parking spaces and beacon devices. We used Android as the platform to implement the proposed car-searching mobile app, and used Bytereal HiBeacon devices to implement the proposed positioning-assisting subsystem. We also deployed the system in a parking lot in our campus for testing. The experimental results verified that the proposed system not only works well, but also provides the car owner with the correct route guidance information.

The on-street parking premium and car drivers' choice between street and garage parking

NARCIS (Netherlands)

Kobus, M.B.W.; Gutierrez Puigarnau, E.; Rietveld, P.; van Ommeren, J.N.

2013-01-01

We introduce a methodology to estimate the effect of parking prices on car drivers' choice between street and garage parking. Our key identifying assumption is that the marginal benefit of parking duration does not depend on this choice. The endogeneity of parking duration is acknowledged in the

A simple statistical signal loss model for deep underground garage

DEFF Research Database (Denmark)

Nguyen, Huan Cong; Gimenez, Lucas Chavarria; Kovacs, Istvan

2016-01-01

In this paper we address the channel modeling aspects for a deep-indoor scenario with extreme coverage conditions in terms of signal losses, namely underground garage areas. We provide an in-depth analysis in terms of path loss (gain) and large scale signal shadowing, and a propose simple...... propagation model which can be used to predict cellular signal levels in similar deep-indoor scenarios. The proposed frequency-independent floor attenuation factor (FAF) is shown to be in range of 5.2 dB per meter deep....

Justification and choice of hardware for automatic control system by technical means at the garage consumer cooperative

Directory of Open Access Journals (Sweden)

Krasnykh V.Yu.

2017-06-01

Full Text Available the article describes the main system requirements of software of finished products for implementation of an automatic control system by technical means at the garage consumer cooperative.

A Route Guidance System for Car Finding in Indoor Parking Garages

OpenAIRE

Pei-Chun Lee; Sheng-Shih Wang

2016-01-01

This paper presents a route guidance system for car owners to find their cars in parking garages. The presents system comprises a positioning-assisting subsystem and a car-finding mobile app. The positioning-assisting subsystem mainly uses the iBeacon technology for indoor positioning. The car-finding mobile app guides car owners to their cars based on a non-map navigation strategy. This study also designs a virtual coordinate system to support identifying the locations of parking spaces and ...

System Reliability for LED-Based Products

Energy Technology Data Exchange (ETDEWEB)

Davis, J Lynn; Mills, Karmann; Lamvik, Michael; Yaga, Robert; Shepherd, Sarah D; Bittle, James; Baldasaro, Nick; Solano, Eric; Bobashev, Georgiy; Johnson, Cortina; Evans, Amy

2014-04-07

Results from accelerated life tests (ALT) on mass-produced commercially available 6” downlights are reported along with results from commercial LEDs. The luminaires capture many of the design features found in modern luminaires. In general, a systems perspective is required to understand the reliability of these devices since LED failure is rare. In contrast, components such as drivers, lenses, and reflector are more likely to impact luminaire reliability than LEDs.

Can We Afford These Affordances? GarageBand and the Double-Edged Sword of the Digital Audio Workstation

Science.gov (United States)

Bell, Adam Patrick

2015-01-01

The proliferation of computers, tablets, and smartphones has resulted in digital audio workstations (DAWs) such as GarageBand in being some of the most widely distributed musical instruments. Positing that software designers are dictating the music education of DAW-dependent music-makers, I examine the fallacy that music-making applications such…

Research and Implementation of Automatic Fuzzy Garage Parking System Based on FPGA

Directory of Open Access Journals (Sweden)

Wang Kaiyu

2016-01-01

Full Text Available Because of many common scenes of reverse parking in real life, this paper presents a fuzzy controller which accommodates front and back adjustment of vehicle’s body attitude, and based on chaotic-genetic arithmetic to optimize the membership function of this controller, and get a vertical parking fuzzy controller whose simulation result is good .The paper makes the hardware-software embedded design for system based on Field-Programmable Gate Array (FPGA, and set up a 1:10 verification platform of smart car to verify the fuzzy garage parking system with real car. Verification results show that, the system can complete the parking task very well.

A Case Study Exploring the Use of GarageBand[TM] and an Electronic Bulletin Board in Preservice Music Education

Science.gov (United States)

Vratulis, Vetta; Morton, Charlene

2011-01-01

This qualitative research study is an exploration of the merit and shortcomings of using a combination of the music software GarageBand[TM] and an electronic bulletin board to facilitate musical and peer learning in a 3-month elementary music methods curriculum and instruction course. A pedagogical objective of this assignment was to increase the…

Siim Nestor soovitab : Acid Mothers Temple. Dzhäss ja "tõsidus" NYYD Ensemble ilt. Garage, this is paradise. East-West / Siim Nestor

Index Scriptorium Estoniae

Nestor, Siim, 1974-

2002-01-01

Jaapani megaorkestri AMT esinemisest Linnakultuurifestivali üritusel "Operation B" Von Krahlis 8. nov. Estonia kontserdisaalis toimuvast ansambli NYYD kontserdist 11. nov. Klubis Wimbledon 8. nov. toimuvast peost "Garage, this is paradise". Saku Suurhallis toimuvast peost "East West"

Industrial scale garage-type dry fermentation of municipal solid waste to biogas.

Science.gov (United States)

Qian, M Y; Li, R H; Li, J; Wedwitschka, H; Nelles, M; Stinner, W; Zhou, H J

2016-10-01

The objectives of this study was to through monitoring the 1st industrial scale garage-type dry fermentation (GTDF) MSW biogas plant in Bin County, Harbin City, Heilongjiang Province, China, to investigate its anaerobic digestion (AD) performance and the stability of process. After a monitoring period of 180days, the results showed that the volumetric biogas production of the digesters and percolate tank was 0.72 and 2.22m(3) (m(3)d)(-1), respectively, and the specific biogas yield of the feedstock was about 270m(3)CH4tVS(-1), which indicated that the GTDF is appropriate for the Chinese MSW. This paper also raised some problems aimed at improving the process stability and AD efficiency. Copyright © 2016. Published by Elsevier Ltd.

Site-specific standard request for Underground Storage Tanks 1219-U, 1222-U, 2082-U, and 2068-U at the Rust Garage Facility Buildings 9754-1 and 9720-15

International Nuclear Information System (INIS)

1994-08-01

This document is a site-specific standard request for underground storage tanks located at the Rust Garage Facility. These standards are justified based on conclusion derived from the exposure assessment that indicates there is no current or forseeable future human health risk associated with petroleum contaminants on the site, that current and future ecological risks would be generally limited to subsurface species and plant life with roots extending into the area, and that most of the impacted area at the site is covered by asphalt or concrete. The vertical and horizontal extent of soil and ground water contamination are limited to immediate area of the Rust Garage Facility

Computational study of smoke flow control in garage fires and optimization of the ventilation system

Directory of Open Access Journals (Sweden)

Banjac Miloš J.

2009-01-01

Full Text Available With the aim of evaluating capabilities of a ventilation system to control the spread of smoke in the emergency operating mode, thereby providing conditions for safe evacuation of people from a fire-struck area, computational fluid dynamics simulation of a fire in a semi-bedded garage was conducted. Using the experimental results of combustion dynamics of a passenger car on fire, optimal positions of ventilation openings were determined. According to recommendations by DIN EN 12101 standard, the operating modes of a ventilation system were verified and optimal start time of the smoke extraction system was defined.

Assessment of Material Solutions of Multi-level Garage Structure Within Integrated Life Cycle Design Process

Science.gov (United States)

Wałach, Daniel; Sagan, Joanna; Gicala, Magdalena

2017-10-01

The paper presents an environmental and economic analysis of the material solutions of multi-level garage. The construction project approach considered reinforced concrete structure under conditions of use of ordinary concrete and high-performance concrete (HPC). Using of HPC allowed to significant reduction of reinforcement steel, mainly in compression elements (columns) in the construction of the object. The analysis includes elements of the methodology of integrated lice cycle design (ILCD). By making multi-criteria analysis based on established weight of the economic and environmental parameters, three solutions have been evaluated and compared within phase of material production (information modules A1-A3).

Plant growth with Led lighting systems

International Nuclear Information System (INIS)

Campiotti, C.A.; Bernardini, A.; Di Carlo, F.; Scoccianti, M.; Alonzo, G.; Carlino, M.; Dondi, F.; Bibbiani, C.

2009-01-01

Leds lighting is highly relevant for the horticultural industry. Compared to other light sources used for plant production, leds have several properties which are potentially useful in relation to horticulture. However, although LEDs technology has raised strong interest in research for extraterrestrial agriculture, current LEDs panel costs are still too high for commercial adoption in greenhouse sector, and their electrical efficacies do not compete with those of high-pressure sodium lamps, but several manufactures are working to address these issues. When LEDs become practical, their ability to based light sources specifically suitable for photosynthesis and other horticulturally relevant plant properties (i.e. low radiated heat; lighting from within the canopy) will render the narrow band spectrum of LEDs of particular interest for providing light to greenhouse horticulture. A general description of LEDs application and their technical characteristics is briefly reported. [it

Influence of Parking Price on Parking Garage Users’ Behaviour

Directory of Open Access Journals (Sweden)

Jelena Simićević

2012-09-01

Full Text Available Parking charge is a powerful tool for solving parking and traffic congestion problems. In order to achieve the expected effects without any adverse impact it is necessary to understand well the users’ responses to this policy. This paper, based on a sample of interviewed parking garage users, has developed binary logit model for identification and quantification of characteristics of users and trips, on which the acceptance of parking price is dependent. In addition, multinomial logit model has been made in order to predict what the users will opt for when faced with an increase in parking price. For the first time the parameter “shorten duration” has been introduced which has shown to be the most significant in making behaviour-related decisions. The results show that the users with the purpose work are the most sensitive to an increase in parking charge, what can be deemed positive for policy makers. However, great sensitivity of the users with the purpose shopping should cause their concern. The results of the multinomial model show that they would not discontinue coming into the area after all.

Analysis of the Causes of Cracks in the Bottom Floor of the Underground Garage of the Hefei Government Affairs Center by using 3D Finite-Element Analysis

Directory of Open Access Journals (Sweden)

ZHU Lei

2015-09-01

Full Text Available A three-dimensional finite-element software program is used in this study to analyze the causes of cracks in an underground garage. Numerous cracks, serious and regular alike, can be found in the underground garage of the Hefei Government Affairs Center. These cracks are mainly located around the central part of the bottom floor within a 44.6– 57.8 m radius. To explore the causes of the cracks, two attempts are made. On one hand, on-site crack detection and underground water monitoring are conducted. On the other hand, the finite-element software program ANSYS is adopted to establish a finite-element model for the floor–foundation and connecting beam–foundation soil systems of the underground garage. Furthermore, the influences of the underground foundation, underground water level, soil expansion, and Poisson ratio on the bottom floor are calculated and analyzed. On the basis of the calculation and monitoring results, the following conclusion can be made: underground water is the main cause of the bottom floor cracks because underground water exerts a pushing force from the bottom and causes the expansibility of expansive soil. The study aims to provide a theoretical basis for the treatment of cracking in the Hefei Government Affairs Center, and offer a reference for the design, construction, and maintenance of similar projects.

Comparative Assessment of Blood Lead Levels of Automobile Technicians in Organised and Roadside Garages in Lagos, Nigeria

Directory of Open Access Journals (Sweden)

Abdulsalam Saliu

2015-01-01

Full Text Available Occupational exposure to lead is common among automobile technicians and constitutes 0.9% of total global health burden with a majority of cases in developing countries. The aim of this study was to determine and compare the blood lead levels of automobile technicians in roadside and organised garages in Lagos State, Nigeria. This was a comparative cross-sectional study. Data were collected using interviewer-administered questionnaires. Physical examinations were conducted and blood was analysed for lead using atomic spectrophotometery. Statistical analyses were performed to compare the median blood lead levels of each group using the independent sample (Mann-Whitney U test. Seventy-three (40.3% of the organised compared to 59 (34.3% of the roadside groups had high blood lead levels. The organised group had statistically significant higher median blood lead levels of, 66.0 µg/dL than the roadside 43.5 µg/dL (P < 0.05. There was also statistically significant association between high blood lead levels and abnormal discolouration of the mucosa of the mouth in the organised group. Automobile technicians in organised garages in Lagos have higher prevalence of elevated blood lead levels and higher median levels than the roadside group. Preventive strategies against lead exposures should be instituted by the employers and further actions should be taken to minimize exposures, improve work practices, implement engineering controls (e.g., proper ventilation, and ensure the use of personal protective equipment.

Pulmonary function abnormalities associated with exposure to automobile exhaust in a diesel bus garage and roads.

Science.gov (United States)

Chattopadhyay, B P; Alam, J; Roychowdhury, A

2003-01-01

In Kolkata city the road transports are maintained by private and Government organization. A major work force belonged to the State Transport Corporation (KSTC), Government of West-Bengal. The pollution caused by these vehicles affects the workers health and caused different types of respiratory problems. This study was undertaken to assess the pulmonary function status of these workers. City KSTC garage workers were investigated and categorically divided into two group: garage mechanics and the (2) those transporting the passengers (drivers and conductors). Vital capacity (VC), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) were recorded by Spirovit-SP-10 (Schiller Ltd, Switzerland) and Wright's Peak Flow Meter (UK) on 236 workers. The different flow volumes, FEV(1), FEV(1%), and flow rates, FEF(02-121), FEF(25-75%), etc. were calculated. The administrative people had higher PFT than the other categories. Drivers and conductors have almost equal mean PFT values but mechanical workers had slightly higher. PFT values according to different age ranges and duration of exposure showed gradual decrement as age and duration of exposure increased. Non-smokers had higher lung volumes compared to smokers and ex-smokers. Restrictive, obstructive and combined types of impairments were noticed in 28.4%, 1.7% and 2.9%, respectively, workers. The restrictive impairment was found to be 30.4% in conductors; 28.9% in drivers, 27.9% in mechanics and 21.7% in administration people. Obstructive type of impairment was found to be 2.9% in both drivers and conductors. The effect of pollution by dust and fumes may be responsible for these pulmonary function impairments, restrictive impairments being greater.

Report on the investigational study on the technical trend of temperature control materials for high efficiency LED lighting use; Kokoritsu LED shomeiyo no ondo seigyo zairyo no gijutsu doko ni kansuru chosa kenkyu hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

For the purpose of the innovative conservation of lighting use energy, a project is being promoted with the aim of developing light emitted diode (LED) and commercializing lighting use light source substituting for fluorescent light. In this study, the following were conducted: literature survey on Peltier materials as temperature control materials for high efficiency LED lighting and the making of them as elements, extraction of technical subjects in the commercialization of LED cooling use Peltier element materials, market surveys/analyses were made of the fields of application including the LED cooling use field. As a result, for the commercialization of temperature control use Peltier elements of lighting use LED, the desirable performance index is 5x10{sup -5}/K or more. Bi{sub 2}Te{sub 3} elements which are now commercially available as Peltier elements are not good in performance and have the toxicity problem. As a candidate of temperature control use materials of lighting use LED, Mg{sub 2} (Sn, Si) or clathrate system are regarded, but the point, etc. were pointed out that it is necessary to improve thermoelectric characteristics. (NEDO)

Optimal colour quality of LED clusters based on memory colours.

Science.gov (United States)

Smet, Kevin; Ryckaert, Wouter R; Pointer, Michael R; Deconinck, Geert; Hanselaer, Peter

2011-03-28

The spectral power distributions of tri- and tetrachromatic clusters of Light-Emitting-Diodes, composed of simulated and commercially available LEDs, were optimized with a genetic algorithm to maximize the luminous efficacy of radiation and the colour quality as assessed by the memory colour quality metric developed by the authors. The trade-off of the colour quality as assessed by the memory colour metric and the luminous efficacy of radiation was investigated by calculating the Pareto optimal front using the NSGA-II genetic algorithm. Optimal peak wavelengths and spectral widths of the LEDs were derived, and over half of them were found to be close to Thornton's prime colours. The Pareto optimal fronts of real LED clusters were always found to be smaller than those of the simulated clusters. The effect of binning on designing a real LED cluster was investigated and was found to be quite large. Finally, a real LED cluster of commercially available AlGaInP, InGaN and phosphor white LEDs was optimized to obtain a higher score on memory colour quality scale than its corresponding CIE reference illuminant.

LED; Zum Thema LED

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

This collection of articles on the subject of light emitting diodes (LED) provides technical information on LED technology, examines latest developments and provides examples of LED use in practice. An 'ABC' of LED technology is presented and fifteen common LED mistakes are noted. The chances and risks of LED use are discussed as is the retrofitting of lighting installations with LEDs. The use of LEDs in street lighting is examined. The journal also includes interviews with architects and a lighting designer. Practical examples of the use of LEDs include the refurbished parliamentary library in Berne, their use in the bird sanctuary headquarters in Sempach, Switzerland, as well as LED use in sales outlets. Also, the use of LED lighting in a spa gazebo in Lucerne is examined.

LED lighting for greenhouses. Final report; LED belysning til vaeksthuse. Slutrapport

Energy Technology Data Exchange (ETDEWEB)

OEstergaard, J.E. (Syddansk Univ. (SDU). Erhvervsinnovation og Teknologi, Odense (Denmark))

2011-01-15

The project had 3 main objectives: 1) To develop a prototype of a LED-based luminaire that can replace the existing glasshouse horticultural lighting. The project have developed a working prototype and experimentally replaced the traditional HPS luminaires in a controlled growing area. The project succeeded in producing plants of comparable quality. However, the project shows that the prototype can be improved by: x) being further integrated into the existing horticultural production technology (eg climate computers and purchase of electricity) x) adapting configuration of luminaires specifically to each plant variety x) adapting different cooling technologies to match specific customer needs x) In some cases being combined with heat input to optimize the overall economy. 2) To achieve an effective electricity savings of 50-80% - equivalent to a value of approx. DKK 5 million for a medium sized nursery. The verified electricity savings was 40%. In test setups and in well defined and controllable production areas the prototypes achieved electricity savings of > 50%. It is expected that a new generation of LEDs (Q3 2010) will allow for greater power savings. 3) To continue prototype development and initiate commercialization of the project through the company Fionia Lighting A/S. The shareholders of the company have allocated capital to the company to allow us to address the main challenges in commercializing the technology. It is expected that the company will enter a strategic alliance with a major industrial player in the beginning of 2011. (Author)

GATEWAY Demonstrations: Exterior LED Lighting Projects at Princeton University

Energy Technology Data Exchange (ETDEWEB)

Davis, Robert G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Evans, WIlliam E. [Princeton Univ., NJ (United States); Murphy, Arthur [Princeton Univ., NJ (United States); Perrin, Tess [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-10-30

This report focuses on four exterior solid-state lighting projects that have been completed at Princeton since 2008, when the University adopted a comprehensive sustainability plan. Through these initial projects – which include a parking garage, a pedestrian path, and two parking lot installations – the school’s facilities engineering staff learned important lessons about SSL technology and gained experience in dealing with the rapidly changing landscape of lighting manufacturers and their suppliers.

Evaluation of Physico-Chemical and Fungal Species Associated with Oil Contaminated Soil from Selected Automobile Garage in Sokoto Metropolis

Directory of Open Access Journals (Sweden)

Hassan Muhammad Maishanu

2018-03-01

Full Text Available This study was conducted with a view to evaluating the physicochemical and mycological properties of different oil contaminated soils collected from three different automobile garages in Sokoto Metropolis, and uncontaminated soil from the temporary site, Usmanu Danfodiyo University, Sokoto (UDUS was used as the control. The pH was determined using pH meter model Hanna (H1991301, quantity of mineral elements was evaluated in accordance with Murphy and Fungi were isolated from the three oil contaminated samples (A, B. and C and the uncontaminated (sample D as control, this was done by standard procedure using the method of P. Ren, T. Jankun & B. Leaderer. The physical, chemical, and mineral elements from the oil-contaminated soils of the three automobile garages and control. The results of particle soil analysis revealed the high content of sandy soil (96.2 to 87.3 and silt is the lowest with (2.5–0.6. Magnesium had the highest concentration of studied minerals, ranging from 193 to 649.2 mg/kg. while PH result revealed that the soil samples were pH value ranged from (16.85–16.20 in oil Contaminated samples, while the control had 15.90, and electrical conductivity ranged from 12.8–13.8 % and 28 % in control, four fungal isolates Aspergillus sp., Penicillum sp., Mucor sp. and Sporobolomyces sp. were identified based on colonial, sexual and morphological characteristics. These fungal strains can be used in bioremediation process and oil pollution reduction in aquatic ecosystems.

Wind energy. From the garage workshop to a global market. 25 years scientific accompaniment

International Nuclear Information System (INIS)

Hahn, Berthold; Stuebig, Cornelia; Ponick, Bernd; Keller, Sarina; Felder, Martin; Jachmann, Henning

2015-01-01

The plant technology for the use of wind energy on land is so sophisticated that the WEA can be operated as ''normal'' power plants to the grid. Of course, there are still potential for development, for example, in terms of improved reliability, or concerning the fledgling offshore use, always with an emphasis on the simultaneous reduction in costs. Although from the former garages workshops is little remaining, the production techniques are another major issue in terms of quality and costs. The cost of electricity from wind energy is taking account of external costs are already competitive with conventional power generation. To limit the costs of the energy transition one to expect from the wind energy as of the other technologies cost reduction. Various studies show that the wind energy supply in the balance is sufficient several times to provide the expected contribution to supply. [de

Integrated LED/Imaging Illumination Panels Demonstrated within a Small Plant Growth Chamber Project

Data.gov (United States)

National Aeronautics and Space Administration — LED light sources are ideal for plant growth systems. However, commercially available multi-color LED illumination panels are designed and manufactured to produce a...

LEDs Illuminate Bulbs for Better Sleep, Wake Cycles

Science.gov (United States)

2015-01-01

Life on the International Space Station (ISS) wreaks havoc on an astronaut’s biological rhythms, and one way NASA mitigates the problem is through the use of LED lighting to alternately stimulate energy and focus and induce relaxation. Satellite Beach, Florida-based Lighting Science partnered with Kennedy Space Center to commercialize an LED system designed for the ISS, resulting in its DefinityDigital product line of light bulbs now used in numerous homes, hotel chains, and resorts.

Accelerated Stress Testing of Multi-Source LED Products: Horticulture Lamps and Tunable-White Modules

Energy Technology Data Exchange (ETDEWEB)

Lynn Davis, Kelley Rountree, Karmann Mills

2018-03-30

This report discusses the use of accelerated stress testing (AST) to provide insights into the long-term behavior of commercial products utilizing different types of mid-power LEDs (MP-LEDs) integrated into the same LED module. Test results are presented from two commercial lamps intended for use in horticulture applications and one tunable-white LED module intended for use in educational and office lighting applications. Each of these products is designed to provide a custom spectrum for their targeted applications and each achieves this goal in different ways. Consequently, a comparison of the long-term stability of these devices will provide insights regarding approaches that could be used to possibly lengthen the lifetime of SSL products.

Bivariate constant stress degradation model: LED lighting system reliability estimation with two-stage modelling

NARCIS (Netherlands)

Sari, J.K.; Newby, M.J.; Brombacher, A.C.; Tang, L.C.

2009-01-01

Light-emitting diode (LED) lamp has received great attention as a potential replacement for the more commercially available lighting technology, such as incandescence and fluorescence lamps. LED which is the main component of LED lamp has a very long lifetime. This means that no or very few failures

Electrical efficiency and droop in MQW LEDs

Science.gov (United States)

Malyutenko, V. K.

2014-02-01

It is believed that low power conversion efficiency in commercial MQW LEDs occurs as a result of efficiency droop, current-induced dynamic degradation of the internal quantum efficiency, injection efficiency, and extraction efficiency. Broadly speaking, all these "quenching" mechanisms could be referred to as the optical losses. The vast advances of high-power InGaN and AlGaInP MQW LEDs have been achieved by addressing these losses. In contrast to these studies, in this paper we consider an alternative approach to make high-power LEDs more efficient. We identify current-induced electrical efficiency degradation (EED) as a strong limiting factor of power conversion efficiency. We found that EED is caused by current crowding followed by an increase in current-induced series resistance of a device. By decreasing the current spreading length, EED also causes the optical efficiency to degrade and stands for an important aspect of LED performance. This paper gives scientists the opportunity to look for different attributes of EED.

Spectral design flexibility of LED brings better life

Science.gov (United States)

Ou, Haiyan; Corell, Dennis; Ou, Yiyu; Poulsen, Peter B.; Dam-Hansen, Carsten; Petersen, Paul-Michael

2012-03-01

Light-emitting diodes (LEDs) are penetrating into the huge market of general lighting because they are energy saving and environmentally friendly. The big advantage of LED light sources, compared to traditional incandescent lamps and fluorescent light tubes, is the flexible spectral design to make white light using different color mixing schemes. The spectral design flexibility of white LED light sources will promote them for novel applications to improve the life quality of human beings. As an initial exploration to make use of the spectral design flexibility, we present an example: 'no blue' white LED light source for sufferers of disease Porphyria. An LED light source prototype, made of high brightness commercial LEDs applying an optical filter, was tested by a patient suffering from Porphyria. Preliminary results have shown that the sufferer could withstand the light source for much longer time than the standard light source. At last future perspectives on spectral design flexibility of LED light sources improving human being's life will be discussed, with focus on the light and health. The good health is ensured by the spectrum optimized so that vital hormones (melatonin and serotonin) are produced during times when they support human daily rhythm.

High power light emitting diode (LED) arrays versus halogen light polymerization of oral biomaterials: Barcol hardness, compressive strength and radiometric properties.

Science.gov (United States)

Mills, Robin W; Uhl, Alexander; Blackwell, Gordon B; Jandt, Klaus D

2002-07-01

The clinical performance of light polymerized dental composites is greatly influenced by the quality of the light curing unit (LCU) used. Commonly used halogen LCUs have some specific drawbacks such as decreasing light output with time. This may result in a low degree of monomer conversion of the composites with negative clinical implications. Previous studies have shown that blue light emitting diode (LED) LCUs have the potential to polymerize dental composites without having the drawbacks of halogen LCUs. Since these studies were carried out LED technology has advanced significantly and commercial LED LCUs are now becoming available. This study investigates the Barcol hardness as a function of depth, and the compressive strength of dental composites that had been polymerized for 40 or 20s with two high power LED LCU prototypes, a commercial LED LCU, and a commercial halogen LCU. In addition the radiometric properties of the LCUs were characterized. The two high power prototype LED LCUs and the halogen LCU showed a satisfactory and similar hardness-depth performance whereas the hardness of the materials polymerized with the commercial LED LCU rapidly decreased with sample depth and reduced polymerization time (20 s). There were statistically significant differences in the overall compressive strengths of composites polymerized with different LCUs at the 95% significance level (p = 0.0016) with the two high power LED LCU prototypes and the halogen LCU forming a statistically homogenous group. In conclusion, LED LCU polymerization technology can reach the performance level of halogen LCUs. One of the first commercial LED LCUs however lacked the power reserves of the high power LED LCU prototypes.

High Power UV LED Industrial Curing Systems

Energy Technology Data Exchange (ETDEWEB)

Karlicek, Robert, F., Jr; Sargent, Robert

2012-05-14

UV curing is a green technology that is largely underutilized because UV radiation sources like Hg Lamps are unreliable and difficult to use. High Power UV LEDs are now efficient enough to replace Hg Lamps, and offer significantly improved performance relative to Hg Lamps. In this study, a modular, scalable high power UV LED curing system was designed and tested, performing well in industrial coating evaluations. In order to achieve mechanical form factors similar to commercial Hg Lamp systems, a new patent pending design was employed enabling high irradiance at long working distances. While high power UV LEDs are currently only available at longer UVA wavelengths, rapid progress on UVC LEDs and the development of new formulations designed specifically for use with UV LED sources will converge to drive more rapid adoption of UV curing technology. An assessment of the environmental impact of replacing Hg Lamp systems with UV LED systems was performed. Since UV curing is used in only a small portion of the industrial printing, painting and coating markets, the ease of use of UV LED systems should increase the use of UV curing technology. Even a small penetration of the significant number of industrial applications still using oven curing and drying will lead to significant reductions in energy consumption and reductions in the emission of green house gases and solvent emissions.

Investigation of phosphor-LED lamp for real-time half-duplex wireless VLC system

International Nuclear Information System (INIS)

Yeh, Chien-Hung; Chow, Chi-Wai; Chen, Hsing-Yu; Liu, Yen-Liang; Hsu, Dar-Zu

2016-01-01

In this investigation, a 71.3 to 148.4 Mbit s −1 white phosphor-LED visible light communication (VLC) system is proposed and demonstrated under the practical transmission length of 140 to 210 cm. Here, a commercial white-light LED lamp with five cascaded phosphor-LED chips is utilized for illumination and communication simultaneously. In the measurement, we utilize the optical orthogonal frequency division multiplexing quadrature amplitude modulation (OFDM-QAM) with bit-loading algorithm and propose an optimal bias-tee circuit design to improve the modulation bandwidth from 1 MHz to 27 MHz. Moreover, a blue optical filter is not used on the client side. Finally, to realize and demonstrate the real-time transmission performance in the proposed LED VLC system, a commercial OFDM-based digital signal processor (DSP) chip is utilized on the LED lighting side and client side, respectively. Hence, the proposed real-time half-duplex VLC transmission could achieve the 70 Mbit s −1 downstream and upstream data throughputs, under a practical transmission length of 200 cm. (paper)

Site-specific standard request for underground storage tanks 1219-U, 1222-U, 2082-U, and 2068-U at the rust garage facility buildings 9754-1 and 9720-15: Oak Ridge Y-12 Plant, Oak Ridge, Tennessee, Facility ID No. 0-010117

International Nuclear Information System (INIS)

1994-12-01

This document represents a Site-specific Standard Request for underground storage tanks (USTs) 1219-U,1222-U and 2082-U previously located at former Building 9754-1, and tank 2086-U previously located at Building 9720-15, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. The tanks previously contained petroleum products. For the purposes of this report, the two building sites will be regarded as a single UST site and will be referred to as the Rust Garage Facility. The current land use associated with the Y-12 Plant is light industrial and the operational period of the plant is projected to be at least 30 years. Thus, potential future residential exposures are not expected to occur for at least 30 years. Based on the degradation coefficient for benzene (the only carcinogenic petroleum constituent detected in soils or groundwater at the Rust Garage Facility), it is expected that the benzene and other contaminants at the site will likely be reduced prior to expiration of the 30-year plant operational period. As the original sources of petroleum contamination have been removed, and the area of petroleum contamination is limited, a site-specific standard is therefore being requested for the Rust Garage Facility

76 FR 66692 - Executive-Led Trade Mission to Afghanistan

Science.gov (United States)

2011-10-27

... business development trade mission to Kabul, Afghanistan in February 2012. This mission will be led by a..., architecture, transportation and logistics, and infrastructure); mining (including equipment, technology, and.... companies explore long-term business opportunities in Afghanistan and enhance U.S.--Afghan commercial...

40 CFR 52.1135 - Regulation for parking freeze.

Science.gov (United States)

2010-07-01

... facility. (3) The phrase commercial parking space means a space used for parking a vehicle in a commercial..., garage, building or structure, or combination or portion thereof, on or in which motor vehicles are..., the total quantity of commercial parking spaces available for use at the same amounts as were...

Harmonics Study of Common Low Wattage LED Lamps

Directory of Open Access Journals (Sweden)

Ioan Dragoş Deaconu

2017-11-01

Full Text Available This article presents experimental data on Light Emitting Diode (LED lamps of low wattage that are commonly found both in commercial and residential applications. A comparison with the existing regulations is performed. The measurements are performed using power and energy quality analyzer intended also for avionic and military systems.

76 FR 14904 - Executive-Led Trade Mission to Afghanistan

Science.gov (United States)

2011-03-18

... would enhance development of Afghanistan's industrial sector and lead to increased productivity and... business development trade mission to Kabul, Afghanistan in September 2011. This mission will be led by a.... companies explore long-term business opportunities in Afghanistan and enhance U.S.-Afghan commercial...

Meeting the challenges of developing LED-based projection displays

Science.gov (United States)

Geißler, Enrico

2006-04-01

The main challenge in developing a LED-based projection system is to meet the brightness requirements of the market. Therefore a balanced combination of optical, electrical and thermal parameters must be reached to achieve these performance and cost targets. This paper describes the system design methodology for a digital micromirror display (DMD) based optical engine using LEDs as the light source, starting at the basic physical and geometrical parameters of the DMD and other optical elements through characterization of the LEDs to optimizing the system performance by determining optimal driving conditions. LEDs have a luminous flux density which is just at the threshold of acceptance in projection systems and thus only a fully optimized optical system with a matched set of LEDs can be used. This work resulted in two projection engines, one for a compact pocket projector and the other for a rear projection television, both of which are currently in commercialization.

LED-based UV source for monitoring spectroradiometer properties

Science.gov (United States)

Sildoja, Meelis-Mait; Nevas, Saulius; Kouremeti, Natalia; Gröbner, Julian; Pape, Sven; Pendsa, Stefan; Sperfeld, Peter; Kemus, Fabian

2018-06-01

A compact and stable UV monitoring source based on state-of-the-art commercially available ultraviolet light emitting diodes (UV-LEDs) has been developed. It is designed to trace the radiometric stability—both responsivity and wavelength scale—of array spectroradiometers measuring direct solar irradiance in the wavelength range between 300 nm and 400 nm. The spectral irradiance stability of the UV-LED-based light source observed in the laboratory after seasoning (burning-in) the individual LEDs was better than 0.3% over a 12 h period of continuous operation. The integral irradiance measurements of the source over a period of several months, where the UV-LED source was not operated continuously between the measurements, showed stability within 0.3%. In-field measurements of the source with an array spectroradiometer indicated the stability of the source to be within the standard uncertainty of the spectroradiometer calibration, which was within 1% to 2%.

Commercial incineration demonstration

International Nuclear Information System (INIS)

Vavruska, J.S.; Borduin, L.C.

1982-01-01

Low-level radioactive wastes (LLW) generated by nuclear utilities presently are shipped to commercial burial grounds for disposal. Increasing transportation and disposal costs have caused industry to consider incineration as a cost-effective means of volume reduction of combustible LLW. Repeated inquiries from the nuclear industry regarding the applicability of the Los Alamos controlled air incineration (CAI) design led the DOE to initiate a commercial demonstration program in FY-1980. Development studies and results in support of this program involving ion exchange resin incineration and fission/activation product distributions within the Los Alamos CAI are described

BiliLED low cost neonatal phototherapy, from prototype to industry

Energy Technology Data Exchange (ETDEWEB)

Geido, Daniel; Failache, Horacio [Instituto de Fisica de la Facultad de Ingenieria - Universidad de la Republica, Montevideo (Uruguay); Simini, Franco [Nucleo de Ingenieria Biomedica de las Facultades de Medicina e Ingenieria (Uruguay); Hospital de ClInicas. Av Italia S/N. Piso 15 sala 2, 11600 Montevideo (Uruguay)

2007-11-15

BiliLED is a phototherapy instrument designed to reduce bilirrubin blood rates in new born babies with jaundice. The light source is centred at 470 nm with a bandwidth of 35 nm and includes a matrix of 196 (14x14) InGaN LEDs. The optical elements are designed to maximize the light intensity useful for treatment, with a small number of LEDs in a compact and low cost unit. The optic array is such that every LED illuminates all the treatment area, which ensures redundancy and, thus, a high reliability not to be found in single-lamp instruments. Thermal dissipation and cost of BiliLED are both an order-of-magnitude smaller than conventional therapy lamps. BiliLED adjusts coetaneous irradiation with a feedback loop to compensate the loss or aging of LEDs achieving a calibrated light source for over a decade of use. A clinical trial in 20 hyperbilirrubinaemia patients shows 16% bilirrubin degradation within 24 hours of treatment, higher than most lamp phototherapy instruments. The steps from prototype to commercial model are described.

BiliLED low cost neonatal phototherapy, from prototype to industry

Science.gov (United States)

Geido, Daniel; Failache, Horacio; Simini, Franco

2007-11-01

BiliLED is a phototherapy instrument designed to reduce bilirrubin blood rates in new born babies with jaundice. The light source is centred at 470 nm with a bandwidth of 35 nm and includes a matrix of 196 (14×14) InGaN LEDs. The optical elements are designed to maximize the light intensity useful for treatment, with a small number of LEDs in a compact and low cost unit. The optic array is such that every LED illuminates all the treatment area, which ensures redundancy and, thus, a high reliability not to be found in single-lamp instruments. Thermal dissipation and cost of BiliLED are both an order-of-magnitude smaller than conventional therapy lamps. BiliLED adjusts coetaneous irradiation with a feedback loop to compensate the loss or aging of LEDs achieving a calibrated light source for over a decade of use. A clinical trial in 20 hyperbilirrubinaemia patients shows 16% bilirrubin degradation within 24 hours of treatment, higher than most lamp phototherapy instruments. The steps from prototype to commercial model are described.

BiliLED low cost neonatal phototherapy, from prototype to industry

International Nuclear Information System (INIS)

Geido, Daniel; Failache, Horacio; Simini, Franco

2007-01-01

BiliLED is a phototherapy instrument designed to reduce bilirrubin blood rates in new born babies with jaundice. The light source is centred at 470 nm with a bandwidth of 35 nm and includes a matrix of 196 (14x14) InGaN LEDs. The optical elements are designed to maximize the light intensity useful for treatment, with a small number of LEDs in a compact and low cost unit. The optic array is such that every LED illuminates all the treatment area, which ensures redundancy and, thus, a high reliability not to be found in single-lamp instruments. Thermal dissipation and cost of BiliLED are both an order-of-magnitude smaller than conventional therapy lamps. BiliLED adjusts coetaneous irradiation with a feedback loop to compensate the loss or aging of LEDs achieving a calibrated light source for over a decade of use. A clinical trial in 20 hyperbilirrubinaemia patients shows 16% bilirrubin degradation within 24 hours of treatment, higher than most lamp phototherapy instruments. The steps from prototype to commercial model are described

A white–cyan-red LED system for low correlated colour temperature lighting

DEFF Research Database (Denmark)

Chakrabarti, Maumita; Thorseth, Anders; Corell, Dennis Dan

2015-01-01

A white LED complemented by cyan and red LEDs is a good candidate for achieving high colour rendering at low correlated colour temperatures. This is usually very difficult with commercially available white LEDs. In addition, the system is able to replace incandescent lighting in many applications...... to 2400 K. Within this range the white light is characterized by a high general colour rendering index (Ra>90), special colour rendering indices for saturated red objects (R9>85), and low chromaticity distance (Duv) from the Planckian locus (Duv

Characterising and testing deep UV LEDs for use in space applications

International Nuclear Information System (INIS)

Hollington, D; Baird, J T; Sumner, T J; Wass, P J

2015-01-01

Deep ultraviolet (DUV) light sources are used to neutralise isolated test masses in highly sensitive space-based gravitational experiments. An example is the LISA Pathfinder charge management system, which uses low-pressure mercury lamps. A future gravitational-wave observatory such as eLISA will use UV light-emitting diodes (UV LEDs), which offer numerous advantages over traditional discharge lamps. Such devices have limited space heritage but are now available from a number of commercial suppliers. Here we report on a test campaign that was carried out to quantify the general properties of three types of commercially available UV LEDs and demonstrate their suitability for use in space. Testing included general electrical and UV output power measurements, spectral stability, pulsed performance and temperature dependence, as well as thermal vacuum, radiation and vibration survivability. (paper)

Characterising and testing deep UV LEDs for use in space applications

Science.gov (United States)

Hollington, D.; Baird, J. T.; Sumner, T. J.; Wass, P. J.

2015-12-01

Deep ultraviolet (DUV) light sources are used to neutralise isolated test masses in highly sensitive space-based gravitational experiments. An example is the LISA Pathfinder charge management system, which uses low-pressure mercury lamps. A future gravitational-wave observatory such as eLISA will use UV light-emitting diodes (UV LEDs), which offer numerous advantages over traditional discharge lamps. Such devices have limited space heritage but are now available from a number of commercial suppliers. Here we report on a test campaign that was carried out to quantify the general properties of three types of commercially available UV LEDs and demonstrate their suitability for use in space. Testing included general electrical and UV output power measurements, spectral stability, pulsed performance and temperature dependence, as well as thermal vacuum, radiation and vibration survivability.

Conduction-driven cooling of LED-based automotive LED lighting systems for abating local hot spots

Science.gov (United States)

Saati, Ferina; Arik, Mehmet

2018-02-01

Light-emitting diode (LED)-based automotive lighting systems pose unique challenges, such as dual-side packaging (front side for LEDs and back side for driver electronics circuit), size, harsh ambient, and cooling. Packaging for automotive lighting applications combining the advanced printed circuit board (PCB) technology with a multifunctional LED-based board is investigated with a focus on the effect of thermal conduction-based cooling for hot spot abatement. A baseline study with a flame retardant 4 technology, commonly known as FR4 PCB, is first compared with a metal-core PCB technology, both experimentally and computationally. The double-sided advanced PCB that houses both electronics and LEDs is then investigated computationally and experimentally compared with the baseline FR4 PCB. Computational models are first developed with a commercial computational fluid dynamics software and are followed by an advanced PCB technology based on embedded heat pipes, which is computationally and experimentally studied. Then, attention is turned to studying different heat pipe orientations and heat pipe placements on the board. Results show that conventional FR4-based light engines experience local hot spots (ΔT>50°C) while advanced PCB technology based on heat pipes and thermal spreaders eliminates these local hot spots (ΔT<10°C), leading to a higher lumen extraction with improved reliability. Finally, possible design options are presented with embedded heat pipe structures that further improve the PCB performance.

Development and Performance Assessment of White LED Dimmer

Science.gov (United States)

Maiti, Pradip Kr.; Roy, Biswanath

2017-10-01

A microcontroller based electronic dimmer is developed using pulse width modulation technique. This dimmer is controllable by infra-red remote within a distance of 4 m and can be electrically connected between LED module and its driver. The performance of a developed LED dimmer is assessed on basis of variation of the photometric parameters of commercially available warm white and cool white LED luminaire used in indoor lighting applications. Four equally spaced dimming levels are considered to measure luminous efficacy, spectral power distribution, CIE 1931 chromaticity coordinates, CIE 1976 CIELUV color difference, correlated color temperature, general color rendering index and one specific color rendering index for saturated red color sample. Variations of above parameters are found out with reference to the values measured at rated voltage without the developed dimmer. Analysis of experimentally measured data shows that the developed LED dimmer is capable to vary light output of the WLED luminaire within a range of 25-100% without appreciable variation of its photometric and color parameters. The only exception is observed for the luminous efficacy parameter where it shows about 17 and 14.7% reduction for warm white and cool white LED luminaire at 25% dimming level.

"Light-box" accelerated growth of poinsettias: LED-only illumination

Science.gov (United States)

Weerasuriya, Charitha; Detez, Stewart; Hock Ng, Soon; Hughes, Andrew; Callaway, Michael; Harrison, Iain; Katkus, Tomas; Juodkazis, Saulius

2018-01-01

For the current commercialized agricultural industry which requires a reduced product lead time to customer and supply all year round, an artificial light emitting diodes (LEDs)-based illumination has high potential due to high efficiency of electrical-to-light conversion. The main advantage of the deployed Red Green Blue Amber LED lighting system is colour mixing capability, which means ability to generate all the colours in the spectrum by using three or four primary colours LEDs. The accelerated plant growth was carried out in a "light-box" which was made to generate an artificial day/night cycle by moving the colour mixing ratio along the colour temperature curve of the chromaticity diagram. The control group of plants form the same initial batch was grown on the same shelf in a greenhouse at the same conditions with addition of artificial illumination by incandescent lamps for few hours. Costs and efficiency projections of LED lamps for horticultural applications is discussed together with required capital investment. The total cost of the "light-box" including LED lamps and electronics was 850 AUD.

Construction of Tungsten Halogen, Pulsed LED, and Combined Tungsten Halogen-LED Solar Simulators for Solar Cell I-V Characterization and Electrical Parameters Determination

Directory of Open Access Journals (Sweden)

Anon Namin

2012-01-01

Full Text Available I-V characterization of solar cells is generally done under natural sunlight or solar simulators operating in either a continuous mode or a pulse mode. Simulators are classified on three features of irradiance, namely, spectral match with respect to air mass 1.5, spatial uniformity, and temporal stability. Commercial solar simulators use Xenon lamps and halogen lamps, whereas LED-based solar simulators are being developed. In this work, we build and test seven simulators for solar cell characterization, namely, one tungsten halogen simulator, four monochromatic (red, green, blue, and white LED simulators, one multicolor LED simulator, and one tungsten halogen-blue LED simulator. The seven simulators provide testing at nonstandard test condition. High irradiance from simulators is obtained by employing elevated supply voltage to tungsten halogen lamps and high pulsing voltages to LEDs. This new approach leads to higher irradiance not previously obtained from tungsten halogen lamps and LEDs. From I-V curves, electrical parameters of solar cell are made and corrected based on methods recommended in the IEC 60891 Standards. Corrected values obtained from non-STC measurements are in good agreement with those obtained from Class AAA solar simulator.

Optimization of colour quality of LED lighting with reference to memory colours

OpenAIRE

Smet, Kevin; Ryckaert, Wouter; Pointer, Michael R.; Deconinck, Geert; Hanselaer, Peter

2012-01-01

Simulated and real tri- and tetrachromatic light-emitting-diode (LED) clusters were optimized for luminous efficacy of radiation (LER) and the memory colour quality metric developed by the authors. The simulated clusters showed no significant differences in achievable colour quality and LER between the different cluster types investigated. The real clusters (composed of commercially available LEDs) showed substantial differences in achievable colour quality and LER between the different clus...

High-power LEDs for plant cultivation

Science.gov (United States)

Tamulaitis, Gintautas; Duchovskis, Pavelas; Bliznikas, Zenius; Breive, Kestutis; Ulinskaite, Raimonda; Brazaityte, Ausra; Novickovas, Algirdas; Zukauskas, Arturas; Shur, Michael S.

2004-10-01

We report on high-power solid-state lighting facility for cultivation of greenhouse vegetables and on the results of the study of control of photosynthetic activity and growth morphology of radish and lettuce imposed by variation of the spectral composition of illumination. Experimental lighting modules (useful area of 0.22 m2) were designed based on 4 types of high-power light-emitting diodes (LEDs) with emission peaked in red at the wavelengths of 660 nm and 640 nm (predominantly absorbed by chlorophyll a and b for photosynthesis, respectively), in blue at 455 nm (phototropic function), and in far-red at 735 nm (important for photomorphology). Morphological characteristics, chlorophyll and phytohormone concentrations in radish and lettuce grown in phytotron chambers under lighting with different spectral composition of the LED-based illuminator and under illumination by high pressure sodium lamps with an equivalent photosynthetic photon flux density were compared. A well-balanced solid-state lighting was found to enhance production of green mass and to ensure healthy morphogenesis of plants compared to those grown using conventional lighting. We observed that the plant morphology and concentrations of morphologically active phytohormones is strongly affected by the spectral composition of light in the red region. Commercial application of the LED-based illumination for large-scale plant cultivation is discussed. This technology is favorable from the point of view of energy consumption, controllable growth, and food safety but is hindered by high cost of the LEDs. Large scale manufacturing of high-power red AlInGaP-based LEDs emitting at 650 nm and a further decrease of the photon price for the LEDs emitting in the vicinity of the absorption peak of chlorophylls have to be achieved to promote horticulture applications.

LEDs for the Implementation of Advanced Hydrogenation Using Hydrogen Charge-State Control

Directory of Open Access Journals (Sweden)

Chee Mun Chong

2018-01-01

Full Text Available Light-induced degradation (LID of p-type Cz solar cells has plagued the industry for many decades. However, in recent years, new techniques for solving this LID have been developed, with hydrogen passivation of the boron-oxygen defects appearing to be an important contributor to the solution. Advanced hydrogenation approaches involving the control of the charge state for the hydrogen atoms in silicon to enhance their diffusivity and reactivity are developed and evaluated in this work for commercial application using a prototype industrial tool in conjunction with solar cells manufactured on commercial production lines. This prototype tool, unlike the previous successful laser-based laboratory approaches, is based on the use of LEDs for controlling the charge state of the hydrogen atoms. The illumination from the LEDs is also used in this work to passivate process-induced defects and contamination from the respective production lines with significant improvements in both efficiency and stability. The results indicate that the low-cost LED-based industrial tool performs as well as the laser-based laboratory tool for implementing these advanced hydrogen passivation approaches.

Commercial incineration demonstration

International Nuclear Information System (INIS)

Borduin, L.C.; Neuls, A.S.

1981-01-01

Low-level radioactive wastes (LLW) generated by nuclear utilities presently are shipped to commercial burial grounds for disposal. Substantially increasing shipping and disposal charges have sparked renewed industry interest in incineration and other advanced volume reduction techniques as potential cost-saving measures. Repeated inquiries from industry sources regarding LLW applicability of the Los Alamos controlled-air incineration (CAI) design led DOE to initiate this commercial demonstration program in FY-1980. The selected program approach to achieving CAI demonstration at a utility site is a DOE sponsored joint effort involving Los Alamos, a nuclear utility, and a liaison subcontractor. Required development tasks and responsibilities of the particpants are described. Target date for project completion is the end of FY-1985

Lens of controllable optical field with thin film metallic glasses for UV-LEDs.

Science.gov (United States)

Pan, C T; Chen, Y C; Lin, Po-Hung; Hsieh, C C; Hsu, F T; Lin, Po-Hsun; Chang, C M; Hsu, J H; Huang, J C

2014-06-16

In the exposure process of photolithography, a free-form lens is designed and fabricated for UV-LED (Ultraviolet Light-Emitting Diode). Thin film metallic glasses (TFMG) are adopted as UV reflection layers to enhance the irradiance and uniformity. The Polydimethylsiloxane (PDMS) with high transmittance is used as the lens material. The 3-D fast printing is attempted to make the mold of the lens. The results show that the average irradiance can be enhanced by 6.5~6.7%, and high uniformity of 85~86% can be obtained. Exposure on commercial thick photoresist using this UV-LED system shows 3~5% dimensional deviation, lower than the 6~8% deviation for commercial mercury lamp system. This current system shows promising potential to replace the conventional mercury exposure systems.

Evaluation of an LED Retrofit Project at Princeton University's Carl Icahn Laboratory

Energy Technology Data Exchange (ETDEWEB)

Davis, Robert [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Murphy, Arthur [Princeton Univ., NJ (United States); Perrin, Tess [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-11-01

At Princeton University’s Carl Icahn Laboratory, DOE’s Commercial Buildings Integration Program documented the implementation of LED retrofit products for recessed troffers, linear cove lighting, and downlights – as part of Princeton’s first building-wide interior LED project. The conversion to LED enables more extensive use of lighting controls to tailor the lighting to the task and limit the operating hours based on occupancy, and the estimated energy savings including controls is 62% compared to the incumbent system.

Liquid cooling applications on automotive exterior LED lighting

Science.gov (United States)

Aktaş, Mehmet; Şenyüz, Tunç; Şenyıldız, Teoman; Kılıç, Muhsin

2018-02-01

In this study cooling of a LED unit with heatsink and liquid cooling block which is used in automotive head lamp applications has been investigated numerically and experimentally. Junction temperature of a LED which is cooled with heatsink and liquid cooling block obtained in the experiment. 23°C is used both in the simulation and the experiment phase. Liquid cooling block material is choosed aluminium (Al) and polyamide. All tests and simulation are performed with three different flow rate. Temperature distribution of the designed product is investigated by doing the numerical simulations with a commercially software. In the simulations, fluid flow is assumed to be steady, incompressible and laminar and 3 dimensional (3D) Navier-Stokes equations are used. According to the calculations it is obtained that junction temperature is higher in the heatsink design compared to block cooled one. By changing the block material, it is desired to investigate the variation on the LED junction temperature. It is found that more efficient cooling can be obtained in block cooling by using less volume and weight. With block cooling lifetime of LED can be increased and flux loss can be decreased with the result of decreased junction temperature.

Industry Research and Recommendations for New Commercial Buildings

Energy Technology Data Exchange (ETDEWEB)

Hendron, B.; Leach, M.; Gregory, N.; Pless, S.; Selkowitz, S.; Matthew, P.

2014-05-01

Researchers evaluated industry needs and developed logic models to support possible future commercial new construction research and deployment efforts that could be led or supported by DOE's Commercial Building Integration program or other national initiatives. The authors believe that these recommendations support a proposed course of action from the current state of commercial building energy efficiency to a possible long-term goal of achieving significant market penetration of cost-effective NZE buildings in all building sectors and climates by 2030.

Remaining Sites Verification Package for the 100-B-20, 1716-B Maintenance Garage Underground Tank, Waste Site Reclassification Form 2006-019

Energy Technology Data Exchange (ETDEWEB)

L. M. Dittmer

2006-09-27

The 100-B-20 waste site, located in the 100-BC-1 Operable Unit of the Hanford Site, consisted of an underground oil tank that once serviced the 1716-B Maintenance Garage. The selected action for the 100-B-20 waste site involved removal of the oil tanks and their contents and demonstrating through confirmatory sampling that all cleanup goals have been met. In accordance with this evaluation, a reclassification status of interim closed out has been determined. The results demonstrate that the site will support future unrestricted land uses that can be represented by a rural-residential scenario. These results also show that residual concentrations support unrestricted future use of shallow zone soil and that contaminant levels remaining in the soil are protective of groundwater and the Columbia River.

Green energy and large commercial users

International Nuclear Information System (INIS)

Capage, Adam

2000-01-01

The difficulties faced in selling green energy to large commercial users are reviewed in this article. Four steps are identified in helping energy service suppliers (ESP) focus on opportunities for maximising revenue, namely, targeting the best prospects, identifying the right contact person, appealing to the primary contact, and helping contacts to make the sale internally. Companies with environmentally conscious customers and well defined environmental policies and led by those that promote environmental stewardship are recognised as commercial customers most likely to sign a deal for green energy

130 LPW 1000 Lm Warm White LED for Illumination

Energy Technology Data Exchange (ETDEWEB)

Soer, Wouter [Philips Lumileds Lighting Company LLC, San Jose, CA (United States)

2012-12-21

An illumination-grade warm-white LED, having correlated color temperature (CCT) between 2700 and 3500 K and capable of producing 1000 lm output at over 130 lm/W at room temperature, has been developed in this program. The high-power warm-white LED is an ideal source for use in indoor and outdoor lighting applications. Over the two year period, we have made the following accomplishments: • Developed a low-cost high-power white LED package and commercialized a series of products with CCT ranging from 2700 to 5700 K under the product name LUXEON M; • Demonstrated a record efficacy of 124.8 lm/W at a flux of 1023 lm, CCT of 3435 K and color rendering index (CRI) over 80 at room temperature in the productized package; • Demonstrated a record efficacy of 133.1 lm/W at a flux of 1015 lm, CCT of 3475 K and CRI over 80 at room temperature in an R&D package. The new high-power LED package is a die-on-ceramic surface mountable LED package. It has four 2 mm2 InGaN pump dice, flip-chip attached to a ceramic submount in a 2x2 array configuration. The submount design utilizes a design approach that combines a high-thermal- conductivity ceramic core for die attach and a low-cost and low-thermal-conductivity ceramic frame for mechanical support and as optical lens carrier. The LED package has a thermal resistance of less than 1.25 K/W. The white LED fabrication also adopts a new batch level (instead of die-by-die) phosphor deposition process with precision layer thickness and composition control, which provides not only tight color control, but also low cost. The efficacy performance goal was achieved through the progress in following key areas: (1) high-efficiency royal blue pump LED development through active region design and epitaxial growth quality improvement (funded by internal programs); (2) improvement in extraction efficiency from the LED package through improvement of InGaN-die-level and package-level optical extraction efficiency; and (3) improvement in phosphor

Effects of LEDs on chlorophyll fluorescence and secondary metabolites in Phalaenopsis

DEFF Research Database (Denmark)

Ouzounis, T.; Fretté, X.; Rosenqvist, Eva

2015-01-01

Light emitting diodes (LEDs) are solid-state semiconductor devices that have been integrated in current greenhouse systems the last decades as they provide the opportunity to control light spectrum. Commercial production of potted orchids under LEDs has increased throughout the world the past dec...... was a little higher when compared to the control. Quantitation of secondary metabolites was performed by HPLC. The analysis showed that the treatments with additional blue light had the highest amount of flavonoids and carotenoids....

Demonstration of 575-Mb/s downlink and 225-Mb/s uplink bi-directional SCM-WDM visible light communication using RGB LED and phosphor-based LED.

Science.gov (United States)

Wang, Yuanquan; Wang, Yiguang; Chi, Nan; Yu, Jianjun; Shang, Huiliang

2013-01-14

We propose and experimentally demonstrate a novel full-duplex bi-directional subcarrier multiplexing (SCM)-wavelength division multiplexing (WDM) visible light communication (VLC) system based on commercially available red-green-blue (RGB) light emitting diode (LED) and phosphor-based LED (P-LED) with 575-Mb/s downstream and 225-Mb/s upstream transmission, employing various modulation orders of quadrature amplitude modulation (QAM) orthogonal frequency division multiplexing (OFDM). For the downlink, red and green colors/wavelengths are assigned to carry useful information, while blue chip is just kept lighting to maintain the white color illumination, and for the uplink, the low-cost P-LED is implemented. In this demonstration, pre-equalization and post-equalization are also adopted to compensate the severe frequency response of LEDs. Using this scheme, 4-user downlink and 1-user uplink transmission can be achieved. Furthermore, it can support more users by adjusting the bandwidth of each sub-channel. Bit error rates (BERs) of all links are below pre-forward-error-correction (pre-FEC) threshold of 3.8x 10(-3) after 66-cm free-space delivery. The results show that this scheme has great potential in the practical VLC system.

Demonstration Assessment of Light-Emitting Diode (LED) Parking Lot Lighting in Leavenworth, KS

Energy Technology Data Exchange (ETDEWEB)

Myer, Michael; Kinzey, Bruce R.; Curry, Ku' uipo

2011-05-06

This report describes the process and results of a demonstration of solid-state lighting (SSL) technology in a commercial parking lot lighting application, under the U.S. Department of Energy (DOE) Solid-State Lighting Technology GATEWAY Demonstration Program. The parking lot is for customers and employees of a Walmart Supercenter in Leavenworth, Kansas and this installation represents the first use of the LED Parking Lot Performance Specification developed by the DOE’s Commercial Building Energy Alliance. The application is a parking lot covering more than a half million square feet, lighted primarily by light-emitting diodes (LEDs). Metal halide wall packs were installed along the building facade. This site is new construction, so the installed baseline(s) were hypothetical designs. It was acknowledged early on that deviating from Walmart’s typical design would reduce the illuminance on the site. Walmart primarily uses 1000W pulse-start metal halide (PMH) lamps. In order to provide a comparison between both typical design and a design using conventional luminaires providing a lower illuminance, a 400W PMH design was also considered. As mentioned already, the illuminance would be reduced by shifting from the PMH system to the LED system. The Illuminating Engineering Society of North America (IES) provides recommended minimum illuminance values for parking lots. All designs exceeded the recommended illuminance values in IES RP-20, some by a wider margin than others. Energy savings from installing the LED system compared to the different PMH systems varied. Compared to the 1000W PMH system, the LED system would save 63 percent of the energy. However, this corresponds to a 68 percent reduction in illuminance as well. In comparison to the 400W PMH system, the LED system would save 44 percent of the energy and provide similar minimum illuminance values at the time of relamping. The LED system cost more than either of the PMH systems when comparing initial costs

Design and Manufacture of a Novel LED Table Lamp with Flower Decoration

Directory of Open Access Journals (Sweden)

Tzer-Ming Jeng

2014-08-01

Full Text Available This work involved the design and manufacture of a novel LED table lamp that provides for flower decoration. It is a combination of a normal LED table lamp and attachments holding flower arrangement frogs. In this application the frogs, as used for traditional flower arrangements, became heat sinks for the LED units. They are made of an aluminum alloy to give good heat transfer and dissipation. In any case since they are fixed to the unit they do not need to be very heavy. The design features of this novel flower-arrangement LED table lamp are: (1 the use of a light aluminum alloy flower decoration frog as a heat sink which gives both high heat dissipation and allows decorative flower arrangement; (2 the installation of LED lamps at three points of the same plate above a cylinder covered with a glass lampshade to achieve a beautiful effect; (3 to provide three different lighting modes for reading, use as a night light and for flower decoration. This novel LED table lamp meets all the energy-saving and environmental protection requirements. It has commercial potential in the market for LED lamps.

A thermosyphon heat pipe cooler for high power LEDs cooling

Science.gov (United States)

Li, Ji; Tian, Wenkai; Lv, Lucang

2016-08-01

Light emitting diode (LED) cooling is facing the challenge of high heat flux more seriously with the increase of input power and diode density. The proposed unique thermosyphon heat pipe heat sink is particularly suitable for cooling of high power density LED chips and other electronics, which has a heat dissipation potential of up to 280 W within an area of 20 mm × 22 mm (>60 W/cm2) under natural air convection. Meanwhile, a thorough visualization investigation was carried out to explore the two phase flow characteristics in the proposed thermosyphon heat pipe. Implementing this novel thermosyphon heat pipe heat sink in the cooling of a commercial 100 W LED integrated chip, a very low apparent thermal resistance of 0.34 K/W was obtained under natural air convection with the aid of the enhanced boiling heat transfer at the evaporation side and the enhanced natural air convection at the condensation side.

Development of efficient, radiation-insensitive GaAs:Zn LEDs

International Nuclear Information System (INIS)

Barnes, C.E.

1977-01-01

Although amphoterically Si doped GaAs LEDs are commercially popular because of their high light output, they are extremely sensitive to irradiation. Therefore, it would be desirable to have a viable alternative available for radiation environment applications. In this work it is shown that by increasing the hole concentration in the active region of nonamphoterically doped GaAs LEDs, one can simultaneously achieve high light output and low radiation sensitivity. Experimental results indicate that the minority carrier lifetime is smaller in more heavily doped devices so that the lifetime-damage constant, tau/sub o/K, is also smaller. Hence, the heavily doped devices should have greater radiation hardness. Neutron-induced light output degradation data as a function of hole concentration confirm this conclusion. The results also show that the pre-irradiation light output is greatest in the heavily doped LEDs. The accompanying decrease of tau/sub o/ in the heavily doped devices indicates that the total minority carrier lifetime is at least partially controlled by the radiative lifetime; a requirement for simultaneously achieving radiation hardness and high initial light output. Finally, an experimental comparison with amphoterically Si doped LEDs shows that the heavily doped devices are superior for neutron fluences greater than 2 x 10 12 n/cm 2

White LED with High Package Extraction Efficiency

International Nuclear Information System (INIS)

Yi Zheng; Stough, Matthew

2008-01-01

The goal of this project is to develop a high efficiency phosphor converting (white) Light Emitting Diode (pcLED) 1-Watt package through an increase in package extraction efficiency. A transparent/translucent monolithic phosphor is proposed to replace the powdered phosphor to reduce the scattering caused by phosphor particles. Additionally, a multi-layer thin film selectively reflecting filter is proposed between blue LED die and phosphor layer to recover inward yellow emission. At the end of the project we expect to recycle approximately 50% of the unrecovered backward light in current package construction, and develop a pcLED device with 80 lm/W e using our technology improvements and commercially available chip/package source. The success of the project will benefit luminous efficacy of white LEDs by increasing package extraction efficiency. In most phosphor-converting white LEDs, the white color is obtained by combining a blue LED die (or chip) with a powdered phosphor layer. The phosphor partially absorbs the blue light from the LED die and converts it into a broad green-yellow emission. The mixture of the transmitted blue light and green-yellow light emerging gives white light. There are two major drawbacks for current pcLEDs in terms of package extraction efficiency. The first is light scattering caused by phosphor particles. When the blue photons from the chip strike the phosphor particles, some blue light will be scattered by phosphor particles. Converted yellow emission photons are also scattered. A portion of scattered light is in the backward direction toward the die. The amount of this backward light varies and depends in part on the particle size of phosphors. The other drawback is that yellow emission from phosphor powders is isotropic. Although some backward light can be recovered by the reflector in current LED packages, there is still a portion of backward light that will be absorbed inside the package and further converted to heat. Heat generated

Building a CAR Garage: Preparing for the Delivery of Commercial CAR T Cell Products at Memorial Sloan Kettering Cancer Center.

Science.gov (United States)

Perica, Karlo; Curran, Kevin J; Brentjens, Renier J; Giralt, Sergio A

2018-03-01

Two commercial chimeric antigen receptor (CAR) T cell therapies for CD19-expressing B cell malignancies, Kymriah and Yescarta, have recently been approved by the Food and Drug Administration. The administration of CAR T cells is a complex endeavor involving cell manufacture, tracking and shipping of apheresis products, and management of novel and severe toxicities. At Memorial Sloan Kettering Cancer Center, we have identified 8 essential tasks that define the CAR T cell workflow. In this review, we discuss practical aspects of CAR T cell program development, including clinical, administrative, and regulatory challenges for successful implementation. Copyright © 2018 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Remaining Sites Verification Package for the 100-B-20, 1716-B Maintenance Garage Underground Tank. Attachment to Waste Site Reclassification Form 2006-019

International Nuclear Information System (INIS)

Dittmer, L.M.

2006-01-01

The 100-B-20 waste site, located in the 100-BC-1 Operable Unit of the Hanford Site, consisted of an underground oil tank that once serviced the 1716-B Maintenance Garage. The selected action for the 100-B-20 waste site involved removal of the oil tanks and their contents and demonstrating through confirmatory sampling that all cleanup goals have been met. In accordance with this evaluation, a reclassification status of interim closed out has been determined. The results demonstrate that the site will support future unrestricted land uses that can be represented by a rural-residential scenario. These results also show that residual concentrations support unrestricted future use of shallow zone soil and that contaminant levels remaining in the soil are protective of groundwater and the Columbia River

Future Solid State Lighting using LEDs and Diode Lasers

DEFF Research Database (Denmark)

Petersen, Paul Michael

2014-01-01

applications. Within the coming years, it is expected that the efficiency of blue laser diodes will approach the efficiency of infrared diode lasers. This will enable high efficiency white light generation with very high lumen per watt values. SSL today is mainly based on phosphor converted blue light emitting......Lighting accounts for 20% of all electrical energy usage. Household lighting and commercial lighting such as public and street lighting are responsible for significant greenhouse gas emissions. Therefore, currently many research initiatives focus on the development of new light sources which shows...... significant savings. Solid state lighting (SSL) based on LEDs is today the most efficient light source for generation of high quality white light. Diode lasers, however, have the potential of being more efficient than LEDs for the generation of white light. A major advantage using diode lasers for solid state...

Role and organization of industrial and commercial departments - a region's view

Energy Technology Data Exchange (ETDEWEB)

Blankley, W E; Parsons, B D

1981-01-01

BGC's West Midlands Region possesses substantial industrial and commercial markets that offer sales opportunities in the tariff and contract areas. Growth in these markets is spurring an increase in BGC's nonresidential gas sales. Specific departments within BGC cater to the commercial and industrial sectors and provide engineering support services, thus bolstering the upward sales trend. Recent market changes have led BGC to combine its industrial and commercial departments to streamline the overall marketing and service activities.

Accelerated optical polymer aging studies for LED luminaire applications

Science.gov (United States)

Estupiñán, Edgar; Wendling, Peter; Kostrun, Marijan; Garner, Richard

2013-09-01

There is a need in the lighting industry to design and implement accelerated aging methods that accurately simulate the aging process of LED luminaire components. In response to this need, we have built a flexible and reliable system to study the aging characteristics of optical polymer materials, and we have employed it to study a commercially available LED luminaire diffuser made of PMMA. The experimental system consists of a "Blue LED Emitter" and a working surface. Both the temperatures of the samples and the optical powers of the LEDs are appropriately characterized in the system. Several accelerated aging experiments are carried out at different temperatures and optical powers over a 90 hour period and the measured transmission values are used as inputs to a degradation model derived using plausibility arguments. This model seems capable of predicting the behavior of the material as a function of time, temperature and optical power. The model satisfactorily predicts the measured transmission values of diffusers aged in luminaires at two different times and thus can be used to make application recommendations for this material. Specifically, at 35000 hours (the manufacturer's stated life of the luminaire) and at the typical operational temperature of the diffuser, the model predicts a transmission loss of only a few percent over the original transmission of the material at 450 nm, which renders this material suitable for this application.

Development of a new water sterilization device with a 365 nm UV-LED.

Science.gov (United States)

Mori, Mirei; Hamamoto, Akiko; Takahashi, Akira; Nakano, Masayuki; Wakikawa, Noriko; Tachibana, Satoko; Ikehara, Toshitaka; Nakaya, Yutaka; Akutagawa, Masatake; Kinouchi, Yohsuke

2007-12-01

Ultraviolet (UV) irradiation is an effective disinfection method. In sterilization equipment, a low-pressure mercury lamp emitting an effective germicidal UVC (254 nm) is used as the light source. However, the lamp, which contains mercury, must be disposed of at the end of its lifetime or following damage due to physical shock or vibration. We investigated the suitability of an ultraviolet light-emitting diode at an output wavelength of 365 nm (UVA-LED) as a sterilization device, comparing with the other wavelength irradiation such as 254 nm (a low-pressure mercury lam) and 405 nm (LED). We used a commercially available UVA-LED that emitted light at the shortest wavelength and at the highest output energy. The new sterilization system using the UVA-LED was able to inactivate bacteria, such as Escherichia coli DH5 alpha, Enteropathogenic E. coli, Vibrio parahaemolyticus, Staphylococcus aureus, and Salmonella enterica serovar Enteritidis. The inactivations of the bacteria were dependent on the accumulation of UVA irradiation. Taking advantage of the safety and compact size of LED devices, we expect that the UVA-LED sterilization device can be developed as a new type of water sterilization device.

Introduction: Commercialization of Academic Science and a New Agenda for Science Education

Science.gov (United States)

Irzik, Gürol

2013-01-01

Certain segments of science are becoming increasingly commercialized. This article discusses the commercialization of academic science and its impact on various aspects of science. It also aims to provide an introduction to the articles in this special issue. I briefly describe the major factors that led to this phenomenon, situate it in the…

Fiscal 1997 report on the results of the international standardization R and D. Study of safety of laser and light emitting diodes (LED) for human body; 1997 nendo seika hokokusho kokusai hyojun soseigata kenkyu kaihatsu. Laser, oyobi hakko diode (LED) ni taisuru jintai eno anzensei no kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-03-01

LD and LED are used in a wide range from telecommunication systems to residential/commercial equipment. Optical semiconductor devices existing in the domain between LD and LED are also being commercialized. In the field of this project, there are a lot of contradictions about the international standards. For the purpose of promoting the common understanding of standards and improving the consistency, the paper examined mainly safety, principles of motion and various applications of laser and LED, and developed international standards for the output measuring method. At the same time, the paper systematically studied the biological safety, determined regulatory values which were backed up as safety standards, and proposed/worked out a draft for new international standardization for safety of LED. Further, by the definition of laser in general, standards related to a lot of TCs among ISO and IEC standards were harmonized for the common understanding on the basis of a common idea. 40 refs., 163 figs., 6 tabs.

Fixed-base recycling of contaminated metals in the commercial market

International Nuclear Information System (INIS)

Loiselle, V.

1993-01-01

Since the establishment of the first fixed-base commercial decontamination facility in 1982, commercial processors have cleaned and recycled more than 120 million lb of metals for productive reuse. This represents enough metal to duplicate the Eiffel Tower eight times. This paper examines the economic conditions that led to the foundation of this industry and the types of decontamination technology that have been successfully employed by the processors

User evaluation of eight led light sources with different special colour rendering indices R9

DEFF Research Database (Denmark)

Markvart, Jakob; Iversen, Anne; Logadottir, Asta

2013-01-01

In this study we evaluated the influence of the special colour rendering index R9 on subjective red colour perception and Caucasian skin appearance among untrained test subjects. The light sources tested are commercially available LED based light sources with similar correlated colour temperature...

CALiPER Report 22.1: Photoelectric Performance of LED MR16 Lamps

Energy Technology Data Exchange (ETDEWEB)

Royer, Michael P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Poplawski, Michael E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Brown, Charles C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Merzouk, Massine B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-09-01

This report is a follow-up to CALiPER Application Summary Report 22, which investigated the photometric performance of LED MR16 lamps. The initial report found that many of the LED MR16 lamps did not perform as required by ENERGY STAR based on their equivalency claims, although they generally did provide substantial efficacy advantages compared to halogen MR16 lamps. All testing was completed using laboratory power supplies, with all but one product tested at 12 V AC. In contrast, this report examined the photoelectric performance of the same set of lamps, using commercially available transformers and dimmers as well as laboratory power supplies providing both AC and DC power.

MudGet: Reproduction of the desired lighting environment using a smart-LED

Directory of Open Access Journals (Sweden)

Yong Hwi Kim

2017-07-01

Full Text Available With the emergence of smart LEDs, lighting based interior design is becoming popular. However, most of the smart LED-based lighting systems rely on expert-human intervention to create a desired atmosphere. For convenience, commercial lighting systems offer a number of options but their usability is fairly restricted. Therefore, an intuitive interface is required for novice users to generate the desired lighting environment. In this paper, we have developed a software, named MudGet, which automatically extracts the light mood from a digital image and controls the LED lamps to reproduce a desired lighting effect according to the extracted light mood. In our method, the light mood is regarded as a set of the representative colors of the digital image. The representative colors are extracted by utilizing K-means clustering algorithm. The dimming parameters are set for which each of the LED lamps create the lighting environment with the mood extracted by the software. To evaluate the feasibility of mood reproduction qualitatively, the degree of similarity between the light mood in the digital image and the reproduced result using LEDs is evaluated by a user study under a miniaturized experimental set. We observe that users can easily produce a desired atmosphere through the proposed MudGet software.

Design of an Oximeter Based on LED-LED Configuration and FPGA Technology

OpenAIRE

Stojanovic, Radovan; Karadaglic, Dejan

2013-01-01

A fully digital photoplethysmographic (PPG) sensor and actuator has been developed. The sensing circuit uses one Light Emitting Diode (LED) for emitting light into human tissue and one LED for detecting the reflectance light from human tissue. A Field Programmable Gate Array (FPGA) is used to control the LEDs and determine the PPG and Blood Oxygen Saturation (SpO2). The configurations with two LEDs and four LEDs are developed for measuring PPG signal and Blood Oxygen Saturation (SpO2). N-LEDs...

Polymer dispensing and embossing technology for the lens type LED packaging

Science.gov (United States)

Chien, Chien-Lin Chang; Huang, Yu-Che; Hu, Syue-Fong; Chang, Chung-Min; Yip, Ming-Chuen; Fang, Weileun

2013-06-01

This study presents a ring-type micro-structure design on the substrate and its corresponding micro fabrication processes for a lens-type light-emitting diode (LED) package. The dome-type or crater-type silicone lenses are achieved by a dispensing and embossing process rather than a molding process. Silicone with a high viscosity and thixotropy index is used as the encapsulant material. The ring-type micro structure is adopted to confine the dispensed silicone encapsulant so as to form the packaged lens. With the architecture and process described, this LED package technology herein has three merits: (1) the flexibility of lens-type LED package designs is enhanced; (2) a dome-type package design is used to enhance the intensity; (3) a crater-type package design is used to enhance the view angle. Measurement results show the ratio between the lens height and lens radius can vary from 0.4 to 1 by changing the volume of dispensed silicone. The view angles of dome-type and crater-type packages can reach 155° ± 5° and 175° ± 5°, respectively. As compared with the commercial plastic leaded chip carrier-type package, the luminous flux of a monochromatic blue light LED is improved by 15% by the dome-type package (improved by 7% by the crater-type package) and the luminous flux of a white light LED is improved by 25% by the dome-type package (improved by 13% by the crater-type package). The luminous flux of monochromatic blue light LED and white light LED are respectively improved by 8% and 12% by the dome-type package as compare with the crater-type package.

Strawberry radurisation on a commercial scale

International Nuclear Information System (INIS)

Du Venhage, C.A.

1985-01-01

An international breakthrough was made at Pelindaba in 1981 when laboratory experiments were adjusted to accomodate commercial quantities of strawberries. Theory and practise of the radurisation of strawberries become compatible and led to the successful marketing of 1,6 million punnets of radurised strawberries during the period 1981 to 1984. Several benefits are derived from this technology, making the marketing and distribution of radurised strawberries an accepted and on-going process

Rapid fabrication of microfluidic chips based on the simplest LED lithography

Science.gov (United States)

Li, Yue; Wu, Ping; Luo, Zhaofeng; Ren, Yuxuan; Liao, Meixiang; Feng, Lili; Li, Yuting; He, Liqun

2015-05-01

Microfluidic chips are generally fabricated by a soft lithography method employing commercial lithography equipment. These heavy machines require a critical room environment and high lamp power, and the cost remains too high for most normal laboratories. Here we present a novel microfluidics fabrication method utilizing a portable ultraviolet (UV) LED as an alternative UV source for photolithography. With this approach, we can repeat several common microchannels as do these conventional commercial exposure machines, and both the verticality of the channel sidewall and lithography resolution are proved to be acceptable. Further microfluidics applications such as mixing, blood typing and microdroplet generation are implemented to validate the practicability of the chips. This simple but innovative method decreases the cost and requirement of chip fabrication dramatically and may be more popular with ordinary laboratories.

Rapid fabrication of microfluidic chips based on the simplest LED lithography

International Nuclear Information System (INIS)

Li, Yue; Wu, Ping; Liao, Meixiang; Feng, Lili; Li, Yuting; He, Liqun; Luo, Zhaofeng; Ren, Yuxuan

2015-01-01

Microfluidic chips are generally fabricated by a soft lithography method employing commercial lithography equipment. These heavy machines require a critical room environment and high lamp power, and the cost remains too high for most normal laboratories. Here we present a novel microfluidics fabrication method utilizing a portable ultraviolet (UV) LED as an alternative UV source for photolithography. With this approach, we can repeat several common microchannels as do these conventional commercial exposure machines, and both the verticality of the channel sidewall and lithography resolution are proved to be acceptable. Further microfluidics applications such as mixing, blood typing and microdroplet generation are implemented to validate the practicability of the chips. This simple but innovative method decreases the cost and requirement of chip fabrication dramatically and may be more popular with ordinary laboratories. (paper)

Addendum to the corrective action plan for Underground Storage Tanks 1219-U, 1222-U, 2082-U, 2068-U at the Rust Garage Facility, Buildings 9720-15 and 9754-1: Oak Ridge Y-12 Plant, Oak Ridge, Tennessee, Facility ID number-sign 0-010117

International Nuclear Information System (INIS)

1994-01-01

This document represents an addendum to the Corrective Action Plan (CAP) for underground storage tanks 1219-U, 2082-U, and 2068-U located at Buildings 9720-15 and 9754-1, Oak Ridge Y-12 Plant, Oak Ridge, TN. The site of the four underground storage tanks is commonly referred to as the Rust Garage Facility. The original CAP was submitted to the Tennessee Department of Environment and Conservation (TDEC) for review in May 1992. During the time period after submission of the original CAP for the Rust Garage Facility, Y-12 Plant Underground Storage Tank (UST) Program personnel continued to evaluate improvements that would optimize resources and expedite the activities schedule presented in the original CAP. Based on these determinations, several revisions to the original corrective action process options for remediation of contaminated soils are proposed. The revised approach will involve excavation of the soils from the impacted areas, on-site thermal desorption of soil contaminants, and final disposition of the treated soils by backfilling into the subject site excavations. Based on evaluation of the corrective actions with regard to groundwater, remediation of groundwater under the Y-12 Plant CERCLA Program is proposed for the facility

Shredder and incinerator technology for volume reduction of commercial transuranic wastes

International Nuclear Information System (INIS)

Oma, K.H.

1986-06-01

Pacific Northwest Laboratory (PNL) is evaluating alternatives and developing technology for treatment of radioactive wastes generated during commercial nuclear activities. Transuranic wastes that require volume reduction include spent HEPA filters, sample and analytical cell waste, and general process trash. A review of current technologies for volume reduction of these wastes led to the selection and testing of several low-speed shredder systems and three candidate incineration processes. The incinerators tested were the electrically heated control-led-air, gas-heated controlled-air, and rotary kiln. Equipment tests were conducted using simulated commercial transuranic wastes to provide a data base for the comparison of the various technologies. The electrically driven, low-speed shredder process was selected as the preferred method for size reduction of the wastes prior to incineration. All three incinerators effectively reduced the waste volume. Based on a technical and economic evaluation on the incineration processes, the recommended system for the commercial waste application is the gas-heated controlled-air incinerator with a single stage of shredding for feed pretreatment

Design of an Oximeter Based on LED-LED Configuration and FPGA Technology

Directory of Open Access Journals (Sweden)

Radovan Stojanovic

2013-01-01

Full Text Available A fully digital photoplethysmographic (PPG sensor and actuator has been developed. The sensing circuit uses one Light Emitting Diode (LED for emitting light into human tissue and one LED for detecting the reflectance light from human tissue. A Field Programmable Gate Array (FPGA is used to control the LEDs and determine the PPG and Blood Oxygen Saturation (SpO2. The configurations with two LEDs and four LEDs are developed for measuring PPG signal and Blood Oxygen Saturation (SpO2. N-LEDs configuration is proposed for multichannel SpO2 measurements. The approach resulted in better spectral sensitivity, increased and adjustable resolution, reduced noise, small size, low cost and low power consumption.

Design of an oximeter based on LED-LED configuration and FPGA technology.

Science.gov (United States)

Stojanovic, Radovan; Karadaglic, Dejan

2013-01-04

A fully digital photoplethysmographic (PPG) sensor and actuator has been developed. The sensing circuit uses one Light Emitting Diode (LED) for emitting light into human tissue and one LED for detecting the reflectance light from human tissue. A Field Programmable Gate Array (FPGA) is used to control the LEDs and determine the PPG and Blood Oxygen Saturation (S(p)O(2)). The configurations with two LEDs and four LEDs are developed for measuring PPG signal and Blood Oxygen Saturation (S(p)O(2)). N-LEDs configuration is proposed for multichannel S(p)O(2) measurements. The approach resulted in better spectral sensitivity, increased and adjustable resolution, reduced noise, small size, low cost and low power consumption.

Evaluation of a LED-based flatbed document scanner for radiochromic film dosimetry in transmission mode.

Science.gov (United States)

Lárraga-Gutiérrez, José Manuel; García-Garduño, Olivia Amanda; Treviño-Palacios, Carlos; Herrera-González, José Alfredo

2018-03-01

Flatbed scanners are the most frequently used reading instrument for radiochromic film dosimetry because its low cost, high spatial resolution, among other advantages. These scanners use a fluorescent lamp and a CCD array as light source and detector, respectively. Recently, manufacturers of flatbed scanners replaced the fluorescent lamp by light emission diodes (LED) as a light source. The goal of this work is to evaluate the performance of a commercial flatbed scanner with LED based source light for radiochromic film dosimetry. Film read out consistency, response uniformity, film-scanner sensitivity, long term stability and total dose uncertainty was evaluated. In overall, the performance of the LED flatbed scanner is comparable to that of a cold cathode fluorescent lamp (CCFL). There are important spectral differences between LED and CCFL lamps that results in a higher sensitivity of the LED scanner in the green channel. Total dose uncertainty, film response reproducibility and long-term stability of LED scanner are slightly better than those of the CCFL. However, the LED based scanner has a strong non-uniform response, up to 9%, that must be adequately corrected for radiotherapy dosimetry QA. The differences in light emission spectra between LED and CCFL lamps and its potential impact on film-scanner sensitivity suggest that the design of a dedicated flat-bed scanner with LEDs may improve sensitivity and dose uncertainty in radiochromic film dosimetry. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Influence of the quantum well models on the numerical simulation of planar InGaN/GaN LED results

International Nuclear Information System (INIS)

Podgórski, J; Woźny, J; Lisik, Z

2016-01-01

Within this paper, we present electric model of a light emitting diode (LED) made of gallium nitride (GaN) followed by examples of simulation results obtained by means of Sentaurus software, which is the part of the TCAD package. The aim of this work is to answer the question of whether physical models of quantum wells used in commercial software are suitable for a correct analysis of the lateral LEDs made of GaN. (paper)

Thermal management for LED applications

CERN Document Server

Poppe, András

2014-01-01

Thermal Management for LED Applications provides state-of-the-art information on recent developments in thermal management as it relates to LEDs and LED-based systems and their applications. Coverage begins with an overview of the basics of thermal management including thermal design for LEDs, thermal characterization and testing of LEDs, and issues related to failure mechanisms and reliability and performance in harsh environments. Advances and recent developments in thermal management round out the book with discussions on advances in TIMs (thermal interface materials) for LED applications, advances in forced convection cooling of LEDs, and advances in heat sinks for LED assemblies. This book also: Presents a comprehensive overview of the basics of thermal management as it relates to LEDs and LED-based systems Discusses both design and thermal management considerations when manufacturing LEDs and LED-based systems Covers reliability and performance of LEDs in harsh environments Has a hands-on applications a...

SHORT ANALYSIS OF COMMERCIAL ADVERTISING

Directory of Open Access Journals (Sweden)

VIRGIL - ION POPOVICI

2015-12-01

Full Text Available In DEX, commercial advertising is defined as the (commercial activity which aimes by advertising (by prints, radio, television, movies, etc., to point out public interest on certain goods, books, show, the use of services etc. A famous, advertised product remains in our memory. Many of us ask somehow annoyed: How some of the brands remain in our memory, although we believe that we are not strongly influenced by advertisements? Interest publicity led to the creation of specialized agencies and organizations at a very broad diversification methods but advertising means.With advertising, the companies using various methods and means of popularizing notify the assortment of goods offered for sale population, of its quality, how to use and the price. In this regard propaganda to persuade consumers through various forms of advertising seeks not only to ensure its capture attention and conversion of formats such motivations in buying certain actions.

A simple and low-cost biofilm quantification method using LED and CMOS image sensor.

Science.gov (United States)

Kwak, Yeon Hwa; Lee, Junhee; Lee, Junghoon; Kwak, Soo Hwan; Oh, Sangwoo; Paek, Se-Hwan; Ha, Un-Hwan; Seo, Sungkyu

2014-12-01

A novel biofilm detection platform, which consists of a cost-effective red, green, and blue light-emitting diode (RGB LED) as a light source and a lens-free CMOS image sensor as a detector, is designed. This system can measure the diffraction patterns of cells from their shadow images, and gather light absorbance information according to the concentration of biofilms through a simple image processing procedure. Compared to a bulky and expensive commercial spectrophotometer, this platform can provide accurate and reproducible biofilm concentration detection and is simple, compact, and inexpensive. Biofilms originating from various bacterial strains, including Pseudomonas aeruginosa (P. aeruginosa), were tested to demonstrate the efficacy of this new biofilm detection approach. The results were compared with the results obtained from a commercial spectrophotometer. To utilize a cost-effective light source (i.e., an LED) for biofilm detection, the illumination conditions were optimized. For accurate and reproducible biofilm detection, a simple, custom-coded image processing algorithm was developed and applied to a five-megapixel CMOS image sensor, which is a cost-effective detector. The concentration of biofilms formed by P. aeruginosa was detected and quantified by varying the indole concentration, and the results were compared with the results obtained from a commercial spectrophotometer. The correlation value of the results from those two systems was 0.981 (N = 9, P CMOS image-sensor platform. Copyright © 2014 Elsevier B.V. All rights reserved.

CooLED - efficient LED bulbs with custrom optics - final report

DEFF Research Database (Denmark)

Wolff, Jesper; Corell, Dennis Dan; Dam-Hansen, Carsten

Denne rapport indeholder en beskrivelse af arbejdet udført i og resultaterne af forsknings- og udviklingsprojektet EUDP 64012-0226, CooLED – en ny generation LED Lyskilde for det tidsløse high-end marked....

Broadband radiometric LED measurements

Science.gov (United States)

Eppeldauer, G. P.; Cooksey, C. C.; Yoon, H. W.; Hanssen, L. M.; Podobedov, V. B.; Vest, R. E.; Arp, U.; Miller, C. C.

2016-09-01

At present, broadband radiometric LED measurements with uniform and low-uncertainty results are not available. Currently, either complicated and expensive spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V(λ) function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irradiance meters with spectrally constant response and high-intensity LED irradiance sources were developed here to implement the previously suggested broadband radiometric LED measurement procedure [1, 2]. Using a detector with spectrally constant response, the broadband radiometric quantities of any LEDs or LED groups can be simply measured with low uncertainty without using any source standard. The spectral flatness of filtered-Si detectors and low-noise pyroelectric radiometers are compared. Examples are given for integrated irradiance measurement of UV and blue LED sources using the here introduced reference (standard) pyroelectric irradiance meters. For validation, the broadband measured integrated irradiance of several LED-365 sources were compared with the spectrally determined integrated irradiance derived from an FEL spectral irradiance lamp-standard. Integrated responsivity transfer from the reference irradiance meter to transfer standard and field UV irradiance meters is discussed.

COMMERCIAL SURROGACY: WHAT ROLE FOR LAW IN AUSTRALIA?

Science.gov (United States)

Sifris, Ronli; Ludlow, Karinne; Sifris, Adiva

2015-12-01

This editorial begins by illuminating current conversations regarding the regulation of commercial surrogacy in Australia. It defines "commercial surrogacy" and explains the interaction between changes in social attitudes and changes to the law before setting out the current Australian law and practice in this area. An examination of current domestic law and practice reveals that surrogacy legislation in Australia is mired in inconsistencies and a lack of uniformity but that the one key common element is the prohibition of commercial surrogacy. The inability of couples to access commercial surrogacy within Australia has led to offshore reproductive tourism and unpredictable, contradictory decision-making as the Family Court attempts to apply legislation which was never intended to apply in this context. The editorial then turns to consider the international arena, discussing the approach of the Hague Conference on Private International Law before delving into a human rights analysis of commercial surrogacy arrangements. The adoption of a rights-based approach requires an analysis of this vexed issue from the perspective of the child, surrogate and intending parents. While questions surrounding the human rights implications of legalising commercial surrogacy continue to be the subject of passionate debate, the authors believe that the human rights of all parties are best protected through appropriate regulation rather than absolute prohibition.

Are nurse-led chemotherapy clinics really nurse-led? An ethnographic study.

Science.gov (United States)

Farrell, Carole; Walshe, Catherine; Molassiotis, Alex

2017-04-01

The number of patients requiring ambulatory chemotherapy is increasing year on year, creating problems with capacity in outpatient clinics and chemotherapy units. Although nurse-led chemotherapy clinics have been set up to address this, there is a lack of evaluation of their effectiveness. Despite a rapid expansion in the development of nursing roles and responsibilities in oncology, there is little understanding of the operational aspects of nurses' roles in nurse-led clinics. To explore nurses' roles within nurse-led chemotherapy clinics. A focused ethnographic study of nurses' roles in nurse-led chemotherapy clinics, including semi-structured interviews with nurses. Four chemotherapy units/cancer centres in the UK PARTICIPANTS: Purposive sampling was used to select four cancer centres/units in different geographical areas within the UK operating nurse-led chemotherapy clinics. Participants were 13 nurses working within nurse-led chemotherapy clinics at the chosen locations. Non-participant observation of nurse-led chemotherapy clinics, semi-structured interviews with nurse participants, review of clinic protocols and associated documentation. 61 nurse-patient consultations were observed with 13 nurses; of these 13, interviews were conducted with 11 nurses. Despite similarities in clinical skills training and prescribing, there were great disparities between clinics run by chemotherapy nurses and those run by advanced nurse practitioners. This included the number of patients seen within each clinic, operational aspects, nurses' autonomy, scope of practice and clinical decision-making abilities. The differences highlighted four different levels of nurse-led chemotherapy clinics, based on nurses' autonomy and scope of clinical practice. However, this was heavily influenced by medical consultants. Several nurses perceived they were undertaking holistic assessments, however they were using medical models/consultation styles, indicating medicalization of nurses' roles

Final report LED solutions for public lighting; Eindrapportage LED oplossingen voor openbare verlichting

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-04-15

This report examines if and how LED can be used for public lighting on a large scale. Pilot projects in 29 municipalities were assessed to test the usefulness of LED lighting. This final report provides answers to the questions that relate to the feasibility of the deployment of LED in public lighting and provides some practical pointers. [Dutch] Er is onderzocht of, en zo ja op welke wijze, LED grootschalig toegepast kan worden in de openbare verlichting (OVL). In 29 gemeenten in Nederland zijn proefprojecten geevalueerd om LED verlichting te toetsen op bruikbaarheid. Deze eindrapportage geeft antwoord op vragen die betrekking hebben op de haalbaarheid van de toepassing van LED binnen de OVL en geeft wat praktische aandachtspunten.

The horizontal gender segregation and its consequences in the masculinised occupation of mechanic (M/F in the subsector of motor vehicle repair garages in Spain

Directory of Open Access Journals (Sweden)

María del Mar Maira Vidal

2017-07-01

Full Text Available This paper is based on the results of two research projects of the research group “Women in men’s worlds”: the research project “Women in men’s worlds: Barriers to enter and strategies to overcome them” (Ref.: FEM2011-25228, financed by the National Plan of the Ministry of Economy and Competitiveness between January 2011 and December 2013; and the project “Women in men’s worlds: Socialisation, labour organisation, and image” (CSO2014-54339-P, also financed by the National Plan between September 2015 and September 2018. In both research projects we have analysed occupational horizontal gender segregation in masculinised occupations in Spain. In this paper we present the results of both research projects about female garage mechanics, whose training and occupation reveal a very high rate of gender-related segregation or cases of gender-related discrimination and harassment or sexual harassment.

LED-roulette : LED's vervangen balletje

NARCIS (Netherlands)

Goossens, P.

2007-01-01

Iedereen waagt wel eens een gokje, in een loterij of misschien ook in een casino. Wie droomt er immers niet van om op een gemakkelijke manier rijk te worden? Met de hier beschreven LED-roulette valt weliswaar weinig te winnen, maar het is wel een uitstekende manier om het roulettespel thuis te

Development of a High Irradiance LED Configuration for Small Field of View Motion Estimation of Fertilizer Particles

Directory of Open Access Journals (Sweden)

Simon Cool

2015-11-01

Full Text Available Better characterization of the fertilizer spreading process, especially the fertilizer pattern distribution on the ground, requires an accurate measurement of individual particle properties and dynamics. Both 2D and 3D high speed imaging techniques have been developed for this purpose. To maximize the accuracy of the predictions, a specific illumination level is required. This paper describes the development of a high irradiance LED system for high speed motion estimation of fertilizer particles. A spectral sensitivity factor was used to select the optimal LED in relation to the used camera from a range of commercially available high power LEDs. A multiple objective genetic algorithm was used to find the optimal configuration of LEDs resulting in the most homogeneous irradiance in the target area. Simulations were carried out for different lenses and number of LEDs. The chosen configuration resulted in an average irradiance level of 452 W/m2 with coefficient of variation less than 2%. The algorithm proved superior and more flexible to other approaches reported in the literature and can be used for various other applications.

LED arrays as cost effective and efficient light sources for widefield microscopy.

Directory of Open Access Journals (Sweden)

Dinu F Albeanu

Full Text Available New developments in fluorophores as well as in detection methods have fueled the rapid growth of optical imaging in the life sciences. Commercial widefield microscopes generally use arc lamps, excitation/emission filters and shutters for fluorescence imaging. These components can be expensive, difficult to maintain and preclude stable illumination. Here, we describe methods to construct inexpensive and easy-to-use light sources for optical microscopy using light-emitting diodes (LEDs. We also provide examples of its applicability to biological fluorescence imaging.

Photovoltaic technologies for commercial power generation

International Nuclear Information System (INIS)

Carlson, D.E.

1990-01-01

Photovoltaic power generation is an attractive source of energy since it involves the direct conversion of sunlight into electricity with no moving parts and no pollution. Following the demonstration of the first solar cell 35 years ago at Bell Laboratories, a steady stream of scientific and commercial progress has led to a rapid increase in applications in recent years. The first commercial application of solar cells occurred more than 20 years ago when they were used to supply power for space satellites, and even today photovoltaic arrays are used to supply electricity for most satellites and space probes. This paper reviews the status of the various photovoltaic technologies as well as present applications. The prospects for both distributed and central station grid-connected systems are discussed. The paper concludes with a discussion of the institutional and political factors that will affect the introduction of grid-connected photovoltaic power systems

Dansk LED - Museumsbelysning

DEFF Research Database (Denmark)

Poulsen, Peter Behrensdorff; Dam-Hansen, Carsten; Thorseth, Anders

Projektet har til formål at anvende dansk forskning inden for optik og lys til at realisere innovative energieffektive LED lyssystemer til museumsbranchen.......Projektet har til formål at anvende dansk forskning inden for optik og lys til at realisere innovative energieffektive LED lyssystemer til museumsbranchen....

DOE acceptance of commercial mixed waste -- Studies are under way

Energy Technology Data Exchange (ETDEWEB)

Plummer, T.L. [Dept. of Energy, Washington, DC (United States). Technical Support Program; Owens, C.M. [Idaho National Engineering Lab., Idaho Falls, ID (United States). National Low-Level Waste Management Program

1993-03-01

The topic of the Department of Energy acceptance of commercial mixed waste at DOE facilities has been proposed by host States and compact regions that are developing low-level radioactive waste disposal facilities. States support the idea of DOE accepting commercial mixed waste because (a) very little commercial mixed waste is generated compared to generation by DOE facilities (Department of Energy--26,300 cubic meters annually vs. commercial--3400 cubic meters annually); (b) estimated costs for commercial disposal are estimated to be $15,000 to $40,000 per cubic foot; (c) once treatment capability becomes available, 70% of the current levels of commercial mixed waste will be eliminated, (d) some State laws prohibit the development of mixed waste disposal facilities in their States; (e) DOE is developing a nationwide strategy that will include treatment and disposal capacity for its own mixed waste and the incremental burden on the DOE facilities would be minuscule, and (6) no States are developing mixed waste disposal facilities. DOE senior management has repeatedly expressed willingness to consider investigating the feasibility of DOE accepting commercial mixed waste. In January 1991, Leo Duffy of the Department of energy met with members of the Low-Level Radioactive Waste Forum, which led to an agreement to explore such an arrangement. He stated that this seems like a cost-effective way to solve commercial mixed waste management problems.

Market-driven production of biospecimens and the role of NHS hospital-led biobanks.

Science.gov (United States)

Timmons, Stephen; Vezyridis, Paraskevas

2017-09-01

Biobanks are vital for biospecimen production in research, despite the regulatory, recruitment and commercial difficulties they face. We conducted interviews with clinicians, researchers, volunteers who recruit biobank participants, regulators and NHS managers about the integration of a biobank into an NHS hospital. We show that medical waste collected for biomedical research acquires its socio-ethical and economic value from the level of integration (both technologically and organisationally) of the biobank into the NHS hospital. There is extensive investment in a range of intellectual and commercial relationships and labour among stakeholders involved in the production of biospecimens. It is not only the boundaries of research, clinical care and commercialisation of biospecimens that blur but also those of volunteerism and citizenship. Hospital-led biobanks provide an opportunity to study the intertwining of biomedical innovation and healthcare. © 2017 Foundation for the Sociology of Health & Illness.

Color homogeneity in LED spotlights

NARCIS (Netherlands)

Prins, C.R.

2013-01-01

Color variation in the light output of white LEDs is a common problem in LED lighting. We aim to design LED spotlights with a uniform color output while keeping the cost of the system low and the energy efficiency high. Therefore we design a special optic to eliminate the color variation of the LED.

Real-time implementation of a 1.25-Gbit/s DMT transmitter for robust and low-cost LED-based plastic optical fiber applications

NARCIS (Netherlands)

Lee, S.C.J.; Breyer, F.; Cárdenas, D.; Randel, S.; Koonen, A.M.J.

2009-01-01

Real-time implementation of a DMT transmitter in FPGA is demonstrated for low-cost, standard 1-mm step-index plastic optical fiber applications based on commercial resonant-cavity LED and large-diameter (540 µm) photodiode.

A portable inspection system to estimate direct glare of various LED modules

Science.gov (United States)

Chen, Po-Li; Liao, Chun-Hsiang; Li, Hung-Chung; Jou, Shyh-Jye; Chen, Han-Ting; Lin, Yu-Hsin; Tang, Yu-Hsiang; Peng, Wei-Jei; Kuo, Hui-Jean; Sun, Pei-Li; Lee, Tsung-Xian

2015-07-01

Glare is caused by both direct and indirect light sources and discomfort glare produces visual discomfort, annoyance, or loss in visual performance and visibility. Direct glare is caused by light sources in the field of view whereas reflected glare is caused by bright reflections from polished or glossy surfaces that are reflected toward an individual. To improve visual comfort of our living environment, a portable inspection system to estimate direct glare of various commercial LED modules with the range of color temperature from 3100 K to 5300 K was developed in this study. The system utilized HDR images to obtain the illumination distribution of LED modules and was first calibrated for brightness and chromaticity and corrected with flat field, dark-corner and curvature by the installed algorithm. The index of direct glare was then automatically estimated after image capturing, and the operator can recognize the performance of LED modules and the possible effects on human being once the index was out of expecting range. In the future, we expect that the quick-response smart inspection system can be applied in several new fields and market, such as home energy diagnostics, environmental lighting and UGR monitoring and popularize it in several new fields.

Transformation products formation of ciprofloxacin in UVA/LED and UVA/LED/TiO2 systems: Impact of natural organic matter characteristics.

Science.gov (United States)

Li, Si; Hu, Jiangyong

2018-04-01

The role of natural organic matter (NOM) in contaminants removal by photolysis and photocatalysis has aroused increasing interest. However, evaluation of the influence of NOM characteristics on the transformation products (TPs) formation and transformation pathways of contaminants has rarely been performed. This study investigated the decomposition kinetics, mineralization, TPs formation and transformation pathways of antibiotic ciprofloxacin (CIP) during photolysis and photocatalysis in the presence of three commercial NOM isolates (Sigma-Aldrich humic acid (SAHA), Suwannee River humic acid (SRHA) and Suwannee River NOM (SRNOM)) by using UVA light emitting diode (UVA/LED) as an alternative light source. NOM isolates insignificantly affected CIP photolysis but strongly inhibited CIP photocatalysis due to competitive radical quenching. The inhibitory effect followed the order of SAHA (49.6%) > SRHA (29.9%) > SRNOM (21.2%), consistent with their •OH quenching abilities, SUVA 254 values and orders of aromaticity. Mineralization rates as revealed by F - release were negatively affected by NOM during CIP photocatalysis. TPs arising from hydroxylation and defluorination were generally suppressed by NOM isolates in UVA/LED and UVA/LED/TiO 2 systems. In contrast, dealkylation and oxidation of piperazine ring were promoted by NOM. The enhancement in the apparent formation kinetics (k app ) of TP245, TP291, TP334a, TP334b and TP362 followed the order of SRNOM > SRHA > SAHA. k app values were positively correlated with O/C ratio, carboxyl content, E2/E3 and fluorescence index (FI) of NOM and negatively related with SUVA 254 values. The observed correlations indicate that NOM properties are important in determining the fate and transformation of organic contaminants during photolysis and photocatalysis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comparing Between Commercial and Investment Banking: A Case Study from Iraq

Directory of Open Access Journals (Sweden)

Dr. Majeed Mohsen

2016-11-01

Full Text Available The research aim is to evaluating investment and commercial banking to led the investor who want to be shareholder in equity to the suitable banking in Iraqi environment, which banking is suitable for risk averse and which is suitable for risk seeker, by comparing between depending on market attractiveness and business strength by comparing between Iraqi’s investment and commercial banking for the period (2010-2014, it is evaluate market attractiveness by using banking return, banking risk, banking size, and banking stability and business strength by using market share (competition, and banking development. The data were from financial report used for statistical testing of difference between two means for comparing instead of comparing between variables directly by using t-test between means. The result explained there wasn’t difference between the two banking marketing, but commercial banking was more total risk than investment banking and systematic risk was the most in both banking. Research conclusion the risky environment, is resulting the conservative depositors decreasing the project, and weak effect of globalization on banking, that is resulting nearly same strategies to avoid internal risk by trying to create safely internal environment depending on strategy of less risk through minimizing unsystematic risks which reduce the ability on diversification which led to weak globalization’s effect.

Strengthening Children's Advertising Defenses: The Effects of Forewarning of Commercial and Manipulative Intent.

Science.gov (United States)

Rozendaal, Esther; Buijs, Laura; van Reijmersdal, Eva A

2016-01-01

This study investigated whether a forewarning of advertising's intent can increase children's (N = 159, 8-10 years old) defenses against television commercials to lower their desire for advertised products. Two different forewarnings were tested, one for advertising's commercial intent or warning for the promotional nature, and one for advertising's manipulative intent or warning for the deceptive nature. Results showed that only the warning of manipulative intent prior to advertising exposure was successful in increasing children's advertising defenses. This forewarning activated children's attitudinal advertising literacy (i.e., skepticism toward the commercial), which in turn led to lower advertised product desire. The forewarning of commercial intent was not effective in strengthening children's advertising defenses. These findings have important implications for interventions that aim to lower children's desire for (unhealthy) advertised products by activating their advertising literacy.

Effect of irradiation type (LED or QTH) on photo-activated composite shrinkage strain kinetics, temperature rise, and hardness.

Science.gov (United States)

Hofmann, Norbert; Hugo, Burkard; Klaiber, Bernd

2002-12-01

This study compares commercially available light-emitting diode (LED) lights with a quartz tungsten halogen (QTH) unit for photo-activating resin-based composites (RBC). Shrinkage strain kinetics and temperature within the RBC were measured simultaneously using the 'deflecting disc technique' and a thermocouple. Surface hardness (Knoop) at the bottom of 1.5-mm thick RBC specimens was measured 24 h after irradiation to indicate degree of cure. Irradiation was performed for 40 s using either the continuous or the ramp-curing mode of a QTH and a LED light (800 mW cm(-2) and 320 mW cm(-2), respectively) or the continuous mode of a lower intensity LED light (160 mW cm(-2)). For Herculite XRV and Filtek Z250 (both containing only camphoroquinone as a photo-initiator) the QTH and the stronger LED light produced similar hardness, while in the case of Definite (containing an additional photo-activator absorbing at lower wavelength) lower hardness was observed after LED irradiation. The temperature rise during polymerization and heating from radiation were lower with LED compared to QTH curing. The fastest increase of polymerization contraction was observed after QTH continuous irradiation, followed by the stronger and the weaker LED light in the continuous mode. Ramp curing decreased contraction speed even more. Shrinkage strain after 60 min was greater following QTH irradiation compared with both LED units (Herculite, Definite) or with the weaker LED light (Z250).

LED Technology for Dental Applications

DEFF Research Database (Denmark)

Argyraki, Aikaterini; Ou, Yiyu; Soerensen, L. H.

LEDs have a large potential in many dental and oral applications. Areas such as photo polymerization, fluorescence imaging, photodynamic therapy, and photoactivated disinfection are important future candidates for LED based diagnostics and treatment in dentistry.......LEDs have a large potential in many dental and oral applications. Areas such as photo polymerization, fluorescence imaging, photodynamic therapy, and photoactivated disinfection are important future candidates for LED based diagnostics and treatment in dentistry....

Broadband Radiometric LED Measurements

OpenAIRE

Eppeldauer, G. P.; Cooksey, C. C.; Yoon, H. W.; Hanssen, L. M.; Podobedov, V. B.; Vest, R. E.; Arp, U.; Miller, C. C.

2016-01-01

At present, broadband radiometric measurements of LEDs with uniform and low-uncertainty results are not available. Currently, either complicated and expensive spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V(��) function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irr...

LED lamp color control system and method

Science.gov (United States)

Gaines, James; Clauberg, Bernd; Van Erp, Josephus A.M.

2013-02-05

An LED lamp color control system and method including an LED lamp having an LED controller 58; and a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 determines whether the LED source 80 is in a feedback controllable range, stores measured optical flux for the LED source 80 when the LED source 80 is in the feedback controllable range, and bypasses storing the measured optical flux when the LED source 80 is not in the feedback controllable range.

Plant growth regulation by the light of LEDs; LED ko wo tsukatta shokubutsu saibai gijutsu

Energy Technology Data Exchange (ETDEWEB)

Watanabe, H. [Mitsubishi Chemical Co., Tokyo (Japan). Yokohama Research Center

1996-03-01

Light Emitting Diode (LED) has not only an excellent display function for the luminescent device but also a superior feature without other lamps as light source for plant growth. It was National Aeronautics and Space Administration (NASA) to find out such merit for this light source for plant growth and try at first to use for plant growth at the space. They began to examine the LED application to the light source for the plant growth at the space since a stage at high cost of the LED, to develop some researches centered at cultivation of lettuce, wheat, and others. Finding out future possibility of cost-down of the LEDs on the cost/performance and large merits of the LEDs for control of the plant growth and plant physiology, authors have conducted some cultivation experiments of the plants using the LEDs for light source some years ago. In this papers, characterizations, actual possibility, and future developments of the LEDs for the light sources of the plant growth, are introduced. 5 refs., 4 figs.

Luminescent properties of phosphor converted LED using an orange-emitting Rb{sub 2}CaP{sub 2}O{sub 7}:Eu{sup 2+} phosphor

Energy Technology Data Exchange (ETDEWEB)

Song, Hee Jo; Yim, Dong Kyun [Department of Materials Science and Engineering, College of Engineering, Seoul National University, Daehak-dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Cho, In-Sun [Department of Mechanical Engineering, Stanford University, CA 94305 (United States); Roh, Hee-Suk; Kim, Ju Seong [Department of Materials Science and Engineering, College of Engineering, Seoul National University, Daehak-dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Kim, Dong-Wan, E-mail: dwkim@ajou.ac.kr [Department of Materials Science and Engineering, Ajou University, Woncheon-dong, San 5, Yeongtong-gu, Suwon 443-749 (Korea, Republic of); Hong, Kug Sun, E-mail: kshongss@plaza.snu.ac.kr [Department of Materials Science and Engineering, College of Engineering, Seoul National University, Daehak-dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of)

2012-12-15

Graphical abstract: Display Omitted Highlights: ► Phase-pure Rb{sub 2}CaP{sub 2}O{sub 7}:Eu{sup 2+} powders were synthesized by a solid state reaction process. ► The optimum emission intensity was observed at the Eu{sup 2+} ion concentration of 0.006. ► The dipole–dipole interaction was the major concentration quenching mechanism. ► The pc-LED coated with Rb{sub 2}CaP{sub 2}O{sub 7}:Eu{sup 2+} had higher CRI than commercial red phosphor. -- Abstract: A series of orange-emitting Rb{sub 2}CaP{sub 2}O{sub 7}:Eu{sup 2+} phosphors were synthesized by a conventional solid-state reaction method. The as-prepared phosphors were characterized by X-ray powder diffraction (XRD), fluorescence spectroscopy, and spectroradiometry. XRD showed that all prepared samples exhibited a monoclinic Rb{sub 2}CaP{sub 2}O{sub 7} phase. Fluorescence spectroscopy showed that the photoluminescence efficiency of Rb{sub 2}Ca{sub 1−x}P{sub 2}O{sub 7}:Eu{sub x}{sup 2+} phosphors increased with increasing Eu{sup 2+} concentration until x = 0.006, then decreased at higher concentrations, due to a concentration quenching effect. The thermal activation energy was also measured to be 0.40 eV. Furthermore, a phosphor-converted LED (pc-LED) coated with Rb{sub 2}Ca{sub 0.994}P{sub 2}O{sub 7}:Eu{sub 0.006}{sup 2+} was fabricated, which exhibited bright orange emission under a forward bias, from 200 to 300 mA. The color rendering index (CRI) of pc-LED coated with Rb{sub 2}Ca{sub 0.994}P{sub 2}O{sub 7}:Eu{sub 0.006}{sup 2+} was higher than the CRI of pc-LED coated with commercial red phosphor, due to the broad emission band of Rb{sub 2}CaP{sub 2}O{sub 7}:Eu{sup 2+} phosphor. In applying with three-band pc-LEDs, moreover, white pc-LED using Rb{sub 2}CaP{sub 2}O{sub 7}:Eu{sup 2+} phosphor had a higher CRI, than using commercial phosphor. These results indicated that Rb{sub 2}CaP{sub 2}O{sub 7}:Eu{sup 2+} phosphor could be a good candidate for a near-UV based w-LED.

Color homogeneity in LED spotlights

NARCIS (Netherlands)

Prins, C.R.; Tukker, T.W.; IJzerman, W.L.; Thije Boonkkamp, ten J.H.M.

2014-01-01

LED is a rising technology in the field of lighting. Halogen spotlights are nowadays replaced by LED spotlights because of their energy efficiency and long lifetime. However, color variation in the light output is a common problem. Poorly designed LED spotlights tend to have yellowish or bluish

LED lamp power management system and method

Science.gov (United States)

Gaines, James; Clauberg, Bernd; Van Erp, Josephus A. M.

2013-03-19

An LED lamp power management system and method including an LED lamp having an LED controller 58; a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 reduces power loss in one of the channel switch 62 and the shunt switch 68 when LED lamp electronics power loss (P.sub.loss) exceeds an LED lamp electronics power loss limit (P.sub.lim); and each of the channel switches 62 receives a channel switch control signal 63 from the LED controller 58 and each of the shunt switches 68 receives a shunt switch control signal 69 from the LED controller 58.

Obstructive sleep apnea among commercial motor vehicle drivers: using evidence-based practice to identify risk factors.

Science.gov (United States)

Olszewski, Kimberly; Wolf, Debra

2013-11-01

Commercial motor vehicle driving is a hazardous occupation, having the third highest fatality rate among common U.S. jobs. Among the estimated 14 million U.S. commercial motor vehicle drivers, the prevalence of obstructive sleep apnea is reported to be 17% to 28%. Despite the identified increased prevalence of obstructive sleep apnea among commercial motor vehicle drivers, federal law does not require that they be screened for obstructive sleep apnea. This article presents an evidence-based practice change project; the authors developed, implemented, and evaluated a screening program to identify commercial motor vehicle drivers' risk for obstructive sleep apnea during commercial driver medical examinations. The results of this practice change indicated screening for obstructive sleep apnea during the commercial driver medical examination led to improved identification of obstructive sleep apnea risk among commercial motor vehicle drivers and should be a clinical standard in occupational health clinics. Copyright 2013, SLACK Incorporated.

Are nurse-led chemotherapy clinics really nurse-led? : an ethnographic study

OpenAIRE

Farrell, Carole; Walshe, Catherine Elizabeth; Molassiotis, Alex

2017-01-01

Background: The number of patients requiring ambulatory chemotherapy is increasing year on year, creating problems with capacity in outpatient clinics and chemotherapy units. Although nurse-led chemotherapy clinics have been set up to address this, there is a lack of evaluation of their effectiveness. Despite a rapid expansion in the development of nursing roles and responsibilities in oncology, there is little understanding of the operational aspects of nurses’ roles in nurse-led clinics. Ob...

Advances in LEDs for automotive applications

Science.gov (United States)

Bhardwaj, Jy; Peddada, Rao; Spinger, Benno

2016-03-01

High power LEDs were introduced in automotive headlights in 2006-2007, for example as full LED headlights in the Audi R8 or low beam in Lexus. Since then, LED headlighting has become established in premium and volume automotive segments and beginning to enable new compact form factors such as distributed low beam and new functions such as adaptive driving beam. New generations of highly versatile high power LEDs are emerging to meet these application needs. In this paper, we will detail ongoing advances in LED technology that enable revolutionary styling, performance and adaptive control in automotive headlights. As the standards which govern the necessary lumens on the road are well established, increasing luminance enables not only more design freedom but also headlight cost reduction with space and weight saving through more compact optics. Adaptive headlighting is based on LED pixelation and requires high contrast, high luminance, smaller LEDs with high-packing density for pixelated Matrix Lighting sources. Matrix applications require an extremely tight tolerance on not only the X, Y placement accuracy, but also on the Z height of the LEDs given the precision optics used to image the LEDs onto the road. A new generation of chip scale packaged (CSP) LEDs based on Wafer Level Packaging (WLP) have been developed to meet these needs, offering a form factor less than 20% increase over the LED emitter surface footprint. These miniature LEDs are surface mount devices compatible with automated tools for L2 board direct attach (without the need for an interposer or L1 substrate), meeting the high position accuracy as well as the optical and thermal performance. To illustrate the versatility of the CSP LEDs, we will show the results of, firstly, a reflector-based distributed low beam using multiple individual cavities each with only 20mm height and secondly 3x4 to 3x28 Matrix arrays for adaptive full beam. Also a few key trends in rear lighting and impact on LED light

‘No Blue’ White LED

DEFF Research Database (Denmark)

Ou, Haiyan; Corell, Dennis Dan; Dam-Hansen, Carsten

2010-01-01

This paper explored the feasibility of making a white LED light source by color mixing method without using the blue color. This ‘no blue’ white LED has potential applications in photolithography room illumination, medical treatment and biophotonics research. A no-blue LED was designed......-2005. Even after 15 days of illumination, no effect was observed. So this LED-based solution was demonstrated to be a very promising light source for photolithography room illumination due to its better color rendering in addition to energy efficiency, long life time and design flexibility. Additionally......, and the prototype was fabricated. The spectral power distribution of both the LED bulb and the yellow fluorescent tube was measured. Based on that, colorimetric values were calculated and compared on terms of chromatic coordinates, correlated color temperature, color rendering index, and chromatic deviation...

Perceived learning effectiveness of a course Facebook page: teacher-led versus student-led approach

Directory of Open Access Journals (Sweden)

Tugba Orten Tugrul

2017-01-01

Full Text Available This research aims to compare the perceived effectiveness of teacher -led and student-led content management approaches embraced in a course Facebook page designed to enhance traditional classroom learning. Eighty-five undergraduate marketing course students voluntarily completed a questionnaire composed of two parts; a depiction of a course Facebook page where both teacher and students can share instructional contents, and questions about perceived learning effectiveness. The findings indicate that students have more favorable evaluations of a student-led approach in sharing instructional contents on a course Facebook Page than a teacher-led approach. Additionally, it is shown that instructional contents posted by both teacher and students enhance the overall learning effectiveness of a course Facebook page incorporated into a traditional classroom teaching.

PENGEMBANGAN LAMPU LED DENGAN TEKNOLOGI PHOTOVOLTAIC (LED-PV SEBAGAI ALAT BANTU PENGUMPUL IKAN PADA PERIKANAN BAGAN

Directory of Open Access Journals (Sweden)

Mochamad Arief Sofijanto

2015-03-01

mengetahui perbedaan jumlah hasil tangkapan pada bagan tancap akibat perlakuan warna lampu LED yang berbeda. Metode penelitian yang digunakan adalah deskriptif dan experimental fishing dimana rancangan penelitiannya adalah Rancangan Acak Lengkap (RAL dengan perlakuan warna lampu LED sebanyak 5 jenis warna yaitu merah (A, kuning (B, hijau (C, biru (D, dan putih (E dengan 6 kali ulangan. Secara deskriptif hasil penelitian menunjukkan lampu LED dapat digunakan untuk menggantikan lampu petromaks dan lampu LHE. Diperoleh 17 jenis ikan laut yang tertarik pada cahaya lampu LED yang digunakan. Hasil analisis statistik menunjukkan terdapat perbedaan nyata terhadap hasil tangkapan bagan dengan perlakuan warna lampu LED. Berdasarkan Uji Nyata Terkecil dinyatakan bahwa bagan yang menggunakan warna lampu LED biru mendapatkan hasil tangkapan tertinggi kemudian diikuti oleh warna kuning, hijau, putih dan merah.  The set ‘bagan’ (liftnet fishing gear is a kind of fishing gears which using atificial light as fishes gathering. This fishing gear uses an electric generator to turn on the energy saving lamp which hang on under the set ‘bagan’. The price of gasoline more expensive due to the Indonesia government’s fuel subsidy reduced and this make fishing operation costs more expensive for fishermen. This research using the LED lamps that do not use gasoline as fuel because the LED lamps can use the photovoltaic technology (solar cell system. The purposes of this study were: 1 to find out whether the LED lamps can replace the kerosene lamps and saving energy lamps, 2 to know the different in cath using different colours of LED lamps. The reserach methods are descriptive and experimental fishing which used Completely Randomized Design with LED lamps colour treatments i.e: red (A, yellow (B, green (C, blue (D, and white (E, the number of replications are 6 times. LED lamps can be used to replace the kerosene and saving energy lamps. There were 17 species of

Off-grid energy services for the poor: Introducing LED lighting in the Millennium Villages Project in Malawi

International Nuclear Information System (INIS)

Adkins, Edwin; Eapen, Sandy; Kaluwile, Flora; Nair, Gautam; Modi, Vijay

2010-01-01

Lanterns that use light-emitting diodes (LEDs) powered by batteries, which are in turn charged by grid electricity or small solar panels, have emerged as a cost-competitive alternative to kerosene and other fuel-based lighting technologies, offering brighter light for longer duration at equal or lower cost over time. This paper presents lessons learned from the introduction of solar LED lanterns in rural Malawi. We discuss a market-based program using new and existing local commercial structures such as vendors and cooperatives to sell lanterns to village households without subsidy. The paper addresses issues of enterprise development, community interactions, and survey data on lighting use and expenditure patterns before and after LED lantern introduction. Households that purchased a lantern reported high levels of satisfaction with the LED lanterns as well as savings in annual kerosene expenditure comparable to the price of the lantern. These households also reported monthly incomes comparable to the price of the LED lanterns whereas non-adopters surveyed reported monthly incomes about half this level, suggesting a need for financing options to maximize adoption among poorer populations in rural areas. These results suggest that similar market based models of LED lighting technology dissemination have the potential to be replicated and scaled up in other off-grid regions in developing countries. However, viability of local cooperatives and supply chains for lantern products over the medium-to-long term remain to be assessed.

Noise Annoyance Produced by Commercial Vehicles Transit on Rumble Strips

Science.gov (United States)

Zaiton, Haron; Khairulzan, Yahya; Nadirah, Darus; Nordiana, Mashros; Azril, Hezmi Muhammad; Samah Rosiah, Abu; Mutalif, Abdul Hameed Abdul; Asyraf, Norudin Wan Mohammad; Habab, Abd Halil Muhammad; Zanariah, Jahya; Hanifi, Othman Mohd

2018-03-01

This paper reports on research examining the extent of noise annoyance affecting residents within the vicinity of installation of two types of transverse rumble strips (TRS), namely Middle Overlapped (MO) and Multilayer Overlapping (MLO). In order to assess the noise annoyance in the area, measurements were taken at 7.5m from centre of road with TRS installation using single vehicle test to determine the extent of changes of sound level indices and sound spectrum. Two light and two medium weight commercial vehicles were used. Indicators LAeq, LAFmax, LAImax, LAIeq, and LASmax were used to determine impulsivity that led to noise annoyance. The results showed that, at 30 km/h, all commercial vehicles considered in this study that transited on MO produced impulsive noise, while only light commercial vehicles caused noise annoyance when they transited on MLO. The research also analysed the extent of low-frequency noise and found a significant low-frequency component, which indicated that noise annoyance might arise from the hitting of MO and MLO by the commercial vehicles. For night-time related annoyance, it was suggested that an additional weighting factor could be added to the average A-weighted value during night-time.

Peer-led versus teacher-led AIDS education for female high-school students in Yazd, Islamic Republic of Iran.

Science.gov (United States)

Baghianimoghadam, M H; Forghani, H; Zolghadr, R; Rahaei, Z; Khani, P

2012-04-01

Peer-led programmes on AIDS prevention have shown a good level of effectiveness when tested among high-risk populations. This study compared peer-led and teacher-led methods of education about HIV/AIDS among female high-school students in Yazd city, Islamic Republic of Iran. In 2009 students in 3 high schools were trained by their classmates (peer-led), by the research team (teacher-led) or had no education (controls); 180 students completed a specially designed questionnaire based on the health belief model, before and after the intervention. Post-intervention mean knowledge scores increased 2-fold in the peer-led group, and this was significantly higher than the increase in the teacher-led group scores (1.5-fold). Control group scores were unchanged. In the peer-led programme all of the components of the model were significantly improved whereas in the teacher-led programme, only perceived severity and perceived barriers scored significantly higher after the intervention.

A new approach to preparation of standard LEDs for luminous intensity and flux measurement of LEDs

Science.gov (United States)

Park, Seung-Nam; Park, Seongchong; Lee, Dong-Hoon

2006-09-01

This work presents an alternative approach for preparing photometric standard LEDs, which is based on a novel functional seasoning method. The main idea of our seasoning method is simultaneously monitoring the light output and the junction voltage to obtain quantitative information on the temperature dependence and the aging effect of the LED emission. We suggested a general model describing the seasoning process by taking junction temperature variation and aging effect into account and implemented a fully automated seasoning facility, which is capable of seasoning 12 LEDs at the same time. By independent measurements of the temperature dependence, we confirmed the discrepancy of the theoretical model to be less than 0.5 % and evaluate the uncertainty contribution of the functional seasoning to be less than 0.5 % for all the seasoned samples. To demonstrate assigning the reference value to a standard LED, the CIE averaged LED intensity (ALI) of the seasoned LEDs was measured with a spectroradiometer-based instrument and the measurement uncertainty was analyzed. The expanded uncertainty of the standard LED prepared by the new approach amounts to be 4 % ~ 5 % (k=2) depending on color without correction of spectral stray light in the spectroradiometer.

Light out-coupling from LEDs by means of metal nanoparticles; Lichtauskopplung aus LEDs mittels Metallnanoteilchen

Energy Technology Data Exchange (ETDEWEB)

Goehler, Tino

2010-12-17

The external quantum efficiency of light-emitting diodes (LEDs) based on Al- GaAs/InGaAlP is limited by total internal reflection because of the high refractive index (typically between 3 and 4) of the semiconductor. Metal nanoparticles (MNP) deposited on the surface of the LED can be used as dipole scatterers in order to enhance the emission of the LED. In this thesis, first, single gold nanoparticles of various sizes deposited on such an LED were investigated. A clear enhancement is detected as long as the dipole plasmon resonance of the particle is at a shorter wavelength than the LED emission. If the plasmon resonance coincides with the LED emission or is at a larger wavelength, the enhancement turns into suppression. Numerical simulations indicate that this latter effect is mainly caused by the particle quadrupole resonance producing extra absorption. Arrays of MNPs can be produced by a special mask technique called ''Fischer pattern nanolithography'' and manipulated in shape and size by additional steps. Originally, the MNPs produced by this technique are triangular in shape and turn out to suppress the LED emission. After transformation of the particles to spheres, a clear enhancement was detected. Light that would otherwise remain trapped inside the substrate is coupled out by resonant plasmonic scattering. Investigations on analogous structures on a transparent high-index material (GaP) indicate a stronger coupling between the particles than expected on the basis of literature data. (orig.)

Generation of solar spectrum by using LEDs

Science.gov (United States)

Lu, Pengzhi; Yang, Hua; Pei, Yanrong; Li, Jing; Xue, Bin; Wang, Junxi; Li, Jinmin

2016-09-01

Light emitting diode (LED) has been recognized as an applicable light source for indoor and outdoor lighting, city beautifying, landscape facilities, and municipal engineering etc. Conventional LED has superior characteristics such as long life time, low power consumption, high contrast, and wide viewing angle. Recently, LED with high color-rendering index and special spectral characteristics has received more and more attention. This paper is intended to report a solar spectrum simulated by multichip LED light source. The typical solar spectrum of 5500k released by CIE was simulated as a reference. Four types of LEDs with different spectral power distributions would be used in the LED light source, which included a 430nm LED, a 480nm LED, a 500nm LED and a white LED. In order to obtain better simulation results, the white LED was achieved by a 450nm LED chip with the mixture of phosphor. The phosphor combination was prepared by mixing green phosphor, yellow phosphor and red phosphor in a certain proportion. The multichip LED light source could provide a high fidelity spectral match with the typical solar spectrum of 5500k by adjusting injection current to each device. The luminous flux, CIE chromaticity coordinate x, y, CCT, and Ra were 104.7 lm, 0.3337, 0.3681, 5460K, and 88.6, respectively. Because of high color-rendering index and highly match to the solar spectrum, the multichip LED light source is a competitive candidate for applications where special spectral is required, such as colorimetric measurements, visual inspection, gemstone identification and agriculture.

Verbaalne soolo Jaanus Nõgistolt : Led R-ist, Narva Linna Sümfooniaorkestrist ja Led Zeppelinist / Jaanus Nõgisto ; interv. Margo Pajuste

Index Scriptorium Estoniae

Nõgisto, Jaanus, 1956-

2007-01-01

Rockansambli Led Zeppelini muusikast, ansamblist Led R ja heliplaadist "Led the R Out" räägib kitarrist Jaanus Nõgisto. Led R ja Narva Linna Sümfooniaorkestri kontserdid: 22. juunil Pärnus ja 14. juulil Haapsalu lossihoovis, ansambli Led R kontsert koos Havana Blackiga 3. aug. Sõru sadamas Hiiumaal

In-situ metrology in multiwafer reactors during MOVPE of AIN-based UV-LEDs (Conference Presentation)

Science.gov (United States)

Knauer, Arne; Brunner, Frank; Kolbe, Tim; Hagedorn, Sylvia; Kueller, Viola; Weyers, Markus

2017-02-01

UV-LEDs are of great interest for applications like disinfection, gas sensing, and phototherapy. The cost sensitive LEDs are commonly grown by MOVPE on transparent AlN/sapphire templates. The large thermal and lattice mismatch between AlN and sapphire generates a very high dislocation density (DD) and causes big challenges in strain management. The threading dislocation density should be reduced to the order of low 108cm-2 for high internal efficiency of the AlGaN based UV-LED structures. The TDD will be reduced mainly by dislocation annihilation during the growth of thick Al(Ga)N layers, which is a challenge in terms of strain management. We present how in-situ reflectometry and curvature measurement (EpiCurveTT(at)LayTec) in commercial multiwafer growth reactors helps to optimize the growth processes concerning growth rates, surface roughening and avoidance of layer cracking on 2inch substrates and enhance the reproducibility of epitaxial growth. The growth of up to 3 μm thick planar AlN templates and up-to 10 μm thick AlN/sapphire templates by epitaxial lateral overgrowth of stripe patterned templates for UV-C LED structures will be highlighted. The implementation of different types of AlN/GaN superlattices for the subsequent growth of up to 5μm thick Al0.5Ga0.5N layer for UVB LED structures will be shown. Correlations to ex-situ measurements like X-ray diffraction and TEM analysis of defects in the LED structures will be shown. Some challenges of in-situ control through very narrow viewports as in Close Coupled Showerhead reactors will be discussed as well as the influence of silicon doping on curvature and dislocation density in Al(Ga)N layers.

Lifetime prediction of LED lighting systems considering thermal coupling between LED sources and drivers

DEFF Research Database (Denmark)

Alfarog, Azzarn Orner; Qu, Xiaohui; Wang, Huai

2017-01-01

and accelerate the failure. In this paper, a new thermal model concerning the thermal coupling is proposed with Finite Element Method (FEM) simulation for parameter acquirement. The proposed model has a better estimation of the thermal stresses of key components in the LED lamps and therefore an improved...... separately, and then the thermal design is also optimized independently. In practice, the LED source and driver are usually compacted in a single fixture. The heat dissipated from LED source and driver will be coupled together and affect the heat transfer performance, which may degrade the whole system...

Strengthening Children’s Advertising Defenses: The Effects of Forewarning of Commercial and Manipulative Intent

Science.gov (United States)

Rozendaal, Esther; Buijs, Laura; van Reijmersdal, Eva A.

2016-01-01

This study investigated whether a forewarning of advertising’s intent can increase children’s (N = 159, 8–10 years old) defenses against television commercials to lower their desire for advertised products. Two different forewarnings were tested, one for advertising’s commercial intent or warning for the promotional nature, and one for advertising’s manipulative intent or warning for the deceptive nature. Results showed that only the warning of manipulative intent prior to advertising exposure was successful in increasing children’s advertising defenses. This forewarning activated children’s attitudinal advertising literacy (i.e., skepticism toward the commercial), which in turn led to lower advertised product desire. The forewarning of commercial intent was not effective in strengthening children’s advertising defenses. These findings have important implications for interventions that aim to lower children’s desire for (unhealthy) advertised products by activating their advertising literacy. PMID:27551271

Strengthening Children’s Advertising Defenses: The Effects of Forewarning of Commercial and Manipulative Intent

Directory of Open Access Journals (Sweden)

Esther Rozendaal

2016-08-01

Full Text Available This study investigated whether a forewarning of advertising’s intent can increase children’s (N = 159, 8-10 years old defenses against television commercials to lower their desire for advertised products. Two different forewarnings were tested, one for advertising’s commercial intent or warning for the promotional nature, and one for advertising’s manipulative intent or warning for the deceptive nature. Results showed that only the warning of manipulative intent prior to advertising exposure was successful in increasing children’s advertising defenses. This forewarning activated children’s attitudinal advertising literacy (i.e., skepticism towards the commercial, which in turn led to lower advertised product desire. The forewarning of commercial intent was not effective in strengthening children’s advertising defenses. These findings have important implications for interventions that aim to lower children’s desire for (unhealthy advertised products by activating their advertising literacy.

Self-Excited Single-Stage Power Factor Correction Driving Circuit for LED Lighting

Directory of Open Access Journals (Sweden)

Yong-Nong Chang

2014-01-01

Full Text Available This pa\tper proposes a self-excited single-stage high power factor LED lighting driving circuit. Being featured with power factor correction capability without needing any control devices, the proposed circuit structure is with low cost and suitable for commercial production. The power factor correction function is accomplished by using inductor in combination with a half-bridge quasi resonant converter to achieve active switching and yield out voltage regulation according to load requirement. Furthermore, the zero-voltage switching in the half-bridge converter can be attained to promote the overall performance efficiency of the proposed circuit. Finally, the validity and production availability of the proposed circuit will be verified as well.

Projecting LED product life based on application

Science.gov (United States)

Narendran, Nadarajah; Liu, Yi-wei; Mou, Xi; Thotagamuwa, Dinusha R.; Eshwarage, Oshadhi V. Madihe

2016-09-01

LED products have started to displace traditional light sources in many lighting applications. One of the commonly claimed benefits for LED lighting products is their long useful lifetime in applications. Today there are many replacement lamp products using LEDs in the marketplace. Typically, lifetime claims of these replacement lamps are in the 25,000-hour range. According to current industry practice, the time for the LED light output to reach the 70% value is estimated according to IESNA LM-80 and TM-21 procedures and the resulting value is reported as the whole system life. LED products generally experience different thermal environments and switching (on-off cycling) patterns when used in applications. Current industry test methods often do not produce accurate lifetime estimates for LED systems because only one component of the system, namely the LED, is tested under a continuous-on burning condition without switching on and off, and because they estimate for only one failure type, lumen depreciation. The objective of the study presented in this manuscript was to develop a test method that could help predict LED system life in any application by testing the whole LED system, including on-off power cycling with sufficient dwell time, and considering both failure types, catastrophic and parametric. The study results showed for the LED A-lamps tested in this study, both failure types, catastrophic and parametric, exist. The on-off cycling encourages catastrophic failure, and maximum operating temperature influences the lumen depreciation rate and parametric failure time. It was also clear that LED system life is negatively affected by on-off switching, contrary to commonly held belief. In addition, the study results showed that most of the LED systems failed catastrophically much ahead of the LED light output reaching the 70% value. This emphasizes the fact that life testing of LED systems must consider catastrophic failure in addition to lumen depreciation, and

Perceived Learning Effectiveness of a Course Facebook Page: Teacher-Led versus Student-Led Approach

Science.gov (United States)

Tugrul, Tugba Orten

2017-01-01

This research aims to compare the perceived effectiveness of teacher-led and student-led content management approaches embraced in a course Facebook page designed to enhance traditional classroom learning. Eighty-five undergraduate marketing course students voluntarily completed a questionnaire composed of two parts; a depiction of a course…

Harmonics Monitoring Survey on LED Lamps

Directory of Open Access Journals (Sweden)

Abdelrahman Ahmed Akila

2017-03-01

Full Text Available Light Emitting Diode (LED lamps are being increasingly used in many applications. These LED lamps operate using a driver, which is a switching device. Hence, LED lamps will be a source of harmonics in the power system. These harmonics if not well treated, may cause severe performance and operational problems. In this paper, harmonics (amplitude and phase angles generated by both LED lamps and conventional fluorescent lamps will be studied practically. Then they will be analyzed and evaluated. Compared to each other harmonics generated by both LED and conventional florescent lamps, self mitigation may occur based on the phase angle of these harmonics. All data will be measured using power analyzer and will be done on a sample of actual lamps.

Standardization of UV LED measurements

Science.gov (United States)

Eppeldauer, G. P.; Larason, T. C.; Yoon, H. W.

2015-09-01

Traditionally used source spectral-distribution or detector spectral-response based standards cannot be applied for accurate UV LED measurements. Since the CIE standardized rectangular-shape spectral response function for UV measurements cannot be realized with small spectral mismatch when using filtered detectors, the UV measurement errors can be several times ten percent or larger. The UV LEDs produce broadband radiation and both their peaks or spectral bandwidths can change significantly. The detectors used for the measurement of these LEDs also have different spectral bandwidths. In the discussed example, where LEDs with 365 nm peak are applied for fluorescent crack-recognition using liquid penetrant (non-destructive) inspection, the broadband radiometric LED (signal) measurement procedure is standardized. A UV LED irradiance-source was calibrated against an FEL lamp standard to determine its spectral irradiance. The spectral irradiance responsivity of a reference UV meter was also calibrated. The output signal of the reference UV meter was calculated from the spectral irradiance of the UV source and the spectral irradiance responsivity of the reference UV meter. From the output signal, both the integrated irradiance (in the reference plane of the reference meter) and the integrated responsivity of the reference meter were determined. Test UV meters calibrated for integrated responsivity against the reference UV meter, can be used to determine the integrated irradiance from a field UV source. The obtained 5 % (k=2) measurement uncertainty can be decreased when meters with spectral response close to a constant value are selected.

USER EVALUATION OF EIGHT LED LIGHT SOURCES WITH DIFFERENTSPECIAL COLOUR RENDERING INDICES R9

DEFF Research Database (Denmark)

Markvart, Jakob; Iversen, Anne; Logadóttir, Ásta

2013-01-01

In this study we evaluated the influence of the special colour rendering index R9 on subjective red colour perception and Caucasian skin appearance among untrained test subjects. The light sources tested are commercially available LED based light sources with similar correlated colour temperature...... and general colour rendering index, but with varying R9. It was found that the test subjects in general are more positive towards light sources with higher R9. The shift from a majority of negative responses to a majority of positive responses is found to occur at R9 values of ~20....

Luminescence properties and energy transfer of site-sensitive Ca(6-x-y)Mg(x-z)(PO(4))(4):Eu(y)(2+),Mn(z)(2+) phosphors and their application to near-UV LED-based white LEDs.

Science.gov (United States)

Kwon, Ki Hyuk; Im, Won Bin; Jang, Ho Seong; Yoo, Hyoung Sun; Jeon, Duk Young

2009-12-21

On the basis of the structural information that the host material has excellent charge stabilization, blue-emitting Ca(6-x-y)Mg(x)(PO(4))(4):Eu(y)(2+) (CMP:Eu(2+)) phosphors were synthesized and systematically optimized, and their photoluminescence (PL) properties were evaluated. Depending upon the amount of Mg added, the emission efficiency of the phosphors could be enhanced. The substitution of Eu(2+) affected their maximum wavelength (lambda(max)) and thermal stability because the substitution site of Eu(2+) could be varied. To obtain single-phase two-color-emitting phosphors, we incorporated Mn(2+) into CMP:Eu(2+) phosphors. Weak red emission resulting from the forbidden transition of Mn(2+) could be enhanced by the energy transfer from Eu(2+) to Mn(2+) that occurs because of the spectral overlap between the photoluminescence excitation (PLE) spectrum of Mn(2+) and the PL spectrum of Eu(2+). The energy transfer process was confirmed by the luminescence spectra, energy transfer efficiency, and decay curve of the phosphors. Finally, the optimized Ca(6-x-y)Mg(x-z)(PO(4))(4):Eu(y)(2+),Mn(z)(2+) (CMP:Eu(2+),Mn(2+)) phosphors were applied with green emitting Ca(2)MgSi(2)O(7):Eu(2+) (CMS:Eu(2+)) phosphors to ultraviolet (UV) light emitting diode (LED)-pumped white LEDs. The CMS:Eu(2+)-mixed CMP:Eu(2+), Mn(2+)-based white LEDs showed an excellent color rendering index (CRI) of 98 because of the broader emission band and more stable color coordinates than those of commercial Y(3)Al(5)O(12):Ce(3+) (YAG:Ce(3+))-based white LEDs under a forward bias current of 20 mA. The fabricated white LEDs showed very bright natural white light that had the color coordinate of (0.3288, 0.3401), and thus CMP:Eu(2+),Mn(2+) could be regarded as a good candidate for UV LED-based white LEDs.

White LEDs with limit luminous efficacy

Energy Technology Data Exchange (ETDEWEB)

Lisitsyn, V. M.; Stepanov, S. A., E-mail: stepanovsa@tpu.ru; Yangyang, Ju [National Research Tomsk Polytechnic University, 30 Lenin Av., Tomsk, 634050 (Russian Federation); Lukash, V. S. [JSC Research Institute of Semiconductor Devices, 99a Krasnoarmeyskaja St., Tomsk, 634050 (Russian Federation)

2016-01-15

In most promising widespread gallium nitride based LEDs emission is generated in the blue spectral region with a maximum at about 450 nm which is converted to visible light with the desired spectrum by means of phosphor. The thermal energy in the conversion is determined by the difference in the energies of excitation and emission quanta and the phosphor quantum yield. Heat losses manifest themselves as decrease in the luminous efficacy. LED heating significantly reduces its efficiency and life. In addition, while heating, the emission generation output and the efficiency of the emission conversion decrease. Therefore, the reduction of the energy losses caused by heating is crucial for LED development. In this paper, heat losses in phosphor-converted LEDs (hereinafter chips) during spectrum conversion are estimated. The limit values of the luminous efficacy for white LEDs are evaluated.

EDITORIAL: LED light sources (light for the future) LED light sources (light for the future)

Science.gov (United States)

Grandjean, N.

2010-09-01

Generating white light from electricity with maximum efficacy has been a long quest since the first incandescent lamp was invented by Edison at the end of the 19th century. Nowadays, semiconductors are making reality the holy grail of converting electrons into photons with 100% efficiency and with colours that can be mixed for white light illumination. The revolution in solid-state lighting (SSL) dates to 1994 when Nakamura reported the first high-brightness blue LED based on GaN semiconductors. Then, white light was produced by simply combining a blue dye with a yellow phosphor. After more than a decade of intensive research the performance of white LEDs is quite impressive, beating by far the luminous efficacy of compact fluorescent lamps. We are likely close to replacing our current lighting devices by SSL lamps. However, there are still technological and fabrication cost issues that could delay large market penetration of white LEDs. Interestingly, SSL may create novel ways of using light that could potentially limit electricity saving. Whatever the impact of SSL, it will be significant on our daily life. The purpose of this special cluster issue is to produce a snapshot of the current situation of SSL from different viewing angles. In an introductory paper, Tsao and co-workers from Sandia National Laboratories, present an energy-economics perspective of SSL considering societal changes and SSL technology evolution. In a second article, Narukawa et al working at Nichia Corporation—the pioneer and still the leading company in SSL—describe the state of the art of current research products. They demonstrate record performance with white LEDs exhibiting luminous efficacy of 183 lm W-1 at high-current injection. Then, a series of topical papers discuss in detail various aspects of the physics and technology of white LEDs Carrier localization in InGaN quantum wells has been considered the key to white LEDs' success despite the huge density of defects. A

Antibacterial Activity of Probiotic Bacteria Isolated From Broiler Feces and Commercial Strains

Directory of Open Access Journals (Sweden)

Parisa Darabi

2014-07-01

Full Text Available Background: The extensive use of antibiotics in animal farms to promote the growth rate and prevent the enteric pathogen has led to the development of antibiotic-resistant bacteria and drug residues in the birds body. In the recent years, probiotics have been constantly studied for their inhibitory effects on pathogenic bacteria. Objectives: The current study aimed to assess the effect of magnesium oxide on controlling serum phosphorus levels and evaluate its side effects. Materials and Methods: Antibacterial activity of local and commercial probiotic bacteria was investigated using colony overlay assay. Then antibacterial activity of local and commercial probiotics against each pathogen, Salmonella typhimurium, Escherichia coli and Staphylococcus aureus were compared. Results: Local strain of lactic acid bacteria had significantly higher antibacterial activity compared to those of the commercial probiotics. Local probiotics showed a significantly stronger activity against Staphylococcus aureus, Salmonella typhimurium and Escherichia coli compared to all commercial probiotics. Conclusions: Administration of mono strain of Lactobacillus salivarius ES1, or co-administration of ES1 and L. salivarius ES6, is not only more effective than commercial probiotics against Salmonella spp., Staphylococcus spp. and E.coli, but also, will have no negative effects on micro flora balance of local birds.

You can do it! - en beretning om bedstemoderen bag Googles succes

DEFF Research Database (Denmark)

Mogensen, Kirsten

2010-01-01

Garager spiller en stor rolle i Silicon Valleys historier om innovation. Der er fx i Palo Alto Hewlett-Packards gamle garage, som er anerkendt som en af Californiens bevaringsværdige historiske bygninger, og så er der Googles garage i Menlo Park. Erfaringen viser, at det er klogt for en ingeniør...... eller datalog at starte i en lille garage, hvis han satser på en fremtid som it-milliardær, på samme måde som det er almindelig kendt, at enhver avisredaktør med respekt for sig selv startede som avisbud. Men hvis du planlægger at leje en garage i Silicon Valley for at gøre Google-drengene kunsten efter...

Efficacy of embedded nurse-led versus conventional physician-led follow-up in rheumatoid arthritis

DEFF Research Database (Denmark)

de Thurah, Annette; Esbensen, Bente Appel; Roelsgaard, Ida Kristiane

2017-01-01

difference (SMD) -0.17 (95 % CI -1.0 to 0.67), whereas a statistical significant difference in favour of nurse-led follow-up was seen after 2 years (SMD: 0.6 (95% CI -0.00 to 1.20)). CONCLUSION: After 1 year no difference in disease activity, indicated by DAS-28, were found between embedded nurse-led follow...

[LED lights in dermatology].

Science.gov (United States)

Noé, C; Pelletier-Aouizerate, M; Cartier, H

2017-04-01

The use in dermatology of light-emitting diodes (LEDs) continues to be surrounded by controversy. This is due mainly to poor knowledge of the physicochemical phases of a wide range of devices that are difficult to compare to one another, and also to divergences between irrefutable published evidence either at the level of in vitro studies or at the cellular level, and discordant clinical results in a variety of different indications: rejuvenation, acne, wound healing, leg ulcers, and cutaneous inflammatory or autoimmune processes. Therapeutic LEDs can emit wavelengths ranging from the ultraviolet, through visible light, to the near infrared (247-1300 nm), but only certain bands have so far demonstrated any real value. We feel certain that if this article remains factual, then readers will have a different, or at least more nuanced, opinion concerning the use of such LED devices in dermatology. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Celebrity-led development organisations

DEFF Research Database (Denmark)

Budabin, Alexandra Cosima; Rasmussen, Louise Mubanda; Richey, Lisa Ann

2017-01-01

The past decade has seen a frontier open up in international development engagement with the entrance of new actors such as celebrity-led organisations. We explore how such organisations earn legitimacy with a focus on Madonna’s Raising Malawi and Ben Affleck’s Eastern Congo Initiative. The study...... for funding, endorsements, and expertise. We argue that the ways in which celebrity-led organisations establish themselves as legitimate development actors illustrate broader dynamics of the machinery of development.......The past decade has seen a frontier open up in international development engagement with the entrance of new actors such as celebrity-led organisations. We explore how such organisations earn legitimacy with a focus on Madonna’s Raising Malawi and Ben Affleck’s Eastern Congo Initiative. The study...... draws from organisational materials, interviews, mainstream news coverage, and the texts of the celebrities themselves to investigate the construction of authenticity, credibility, and accountability. We find these organisations earn legitimacy and flourish rapidly amid supportive elite networks...

LED-driven backlights for automotive displays

Science.gov (United States)

Strauch, Frank

2007-09-01

As a light source the LED has some advantage over the traditionally used fluorescence tube such as longer life or lower space consumption. Consequently customers are asking for the LED lighting design in their products. We introduced in a company owned backlight the white LED technology. This step opens the possibility to have access to the components in the display market. Instead of having a finalized display product which needs to be integrated in the head unit of a car we assemble the backlight, the glass, own electronics and the housing. A major advantage of this concept is the better control of the heat flow generated by the LEDs to the outer side because only a common housing is used for all the components. Also the requirement for slim products can be fulfilled. As always a new technology doesn't come with advantages only. An LED represents a point source compared to the well-known tube thus requiring a mixing zone for the multiple point sources when they enter a light guide. This zone can't be used in displays because of the lack of homogeneity. It's a design goal to minimize this zone which can be helped by the right choice of the LED in terms of slimness. A step ahead is the implementation of RGB LEDs because of their higher color rendering abilities. This allows for the control of the chromaticity point under temperature change but as a drawback needs a larger mixing zone.

Cryogenic characterization of LEDs for space application

Science.gov (United States)

Carron, Jérôme; Philippon, Anne; How, Lip Sun; Delbergue, Audrey; Hassanzadeh, Sahar; Cillierre, David; Danto, Pascale; Boutillier, Mathieu

2017-09-01

In the frame of EUCLID project, the Calibration Unit of the VIS (VISible Imager) instrument must provide an accurate and well characterized light source for in-flight instrument calibration without noise when it is switched off. The Calibration Unit consists of a set of LEDs emitting at various wavelengths in the visible towards an integrating sphere. The sphere's output provides a uniform illumination over the entire focal plane. Nine references of LEDs from different manufacturers were selected, screened and qualified under cryogenic conditions. Testing this large quantity of samples led to the implementation of automated testing equipment with complete in-situ monitoring of optoelectronic parameters as well as temperature and vacuum values. All the electrical and optical parameters of the LED have been monitored and recorded at ambient and cryogenic temperatures. These results have been compiled in order to show the total deviation of the LED electrical and electro-optical properties in the whole mission and to select the best suitable LED references for the mission. This qualification has demonstrated the robustness of COTS LEDs to operate at low cryogenic temperatures and in the space environment. Then 6 wavelengths were selected and submitted to an EMC sensitivity test at room and cold temperature by counting the number of photons when LEDs drivers are OFF. Characterizations were conducted in the full frequency spectrum in order to implement solutions at system level to suppress the emission of photons when the LED drivers are OFF. LEDs impedance was also characterized at room temperature and cold temperature.

Measurement of the photometric characteristics of LEDs

International Nuclear Information System (INIS)

Nazarenko, L.A.; Zubkov, D.P.

2015-01-01

Proposed and implemented a method for measuring LEDs, which is based on self-calibration of the LED goniophotometer facility by using a trap-detector. Designed and manufactured automated goniophotometer, which provides a measurement of high power LEDs at a specified junction temperature. Designed and experimentally researched the photometer with a photometric sphere based diffuser, which meets all requirements of CIE for photometric measurements of LEDs

Sodium monitoring in commercially processed and restaurant foods.

Science.gov (United States)

Ahuja, Jaspreet K C; Pehrsson, Pamela R; Haytowitz, David B; Wasswa-Kintu, Shirley; Nickle, Melissa; Showell, Bethany; Thomas, Robin; Roseland, Janet; Williams, Juhi; Khan, Mona; Nguyen, Quynhanh; Hoy, Kathy; Martin, Carrie; Rhodes, Donna; Moshfegh, Alanna; Gillespie, Cathleen; Gunn, Janelle; Merritt, Robert; Cogswell, Mary

2015-03-01

Most sodium in the US diet comes from commercially processed and restaurant foods. Sodium reduction in these foods is key to several recent public health efforts. The objective was to provide an overview of a program led by the USDA, in partnership with other government agencies, to monitor sodium contents in commercially processed and restaurant foods in the United States. We also present comparisons of nutrients generated under the program to older data. We track ∼125 commercially processed and restaurant food items ("sentinel foods") annually using information from food manufacturers and periodically by nationwide sampling and laboratory analyses. In addition, we monitor >1100 other commercially processed and restaurant food items, termed "priority-2 foods" (P2Fs) biennially by using information from food manufacturers. These foods serve as indicators for assessing changes in the sodium content of commercially processed and restaurant foods in the United States. We sampled all sentinel foods nationwide and reviewed all P2Fs in 2010-2013 to determine baseline sodium concentrations. We updated sodium values for 73 sentinel foods and 551 P2Fs in the USDA's National Nutrient Database for Standard Reference (releases 23-26). Sodium values changed by at least 10% for 43 of the sentinel foods, which, for 31 foods, including commonly consumed foods such as bread, tomato catsup, and potato chips, the newer sodium values were lower. Changes in the concentrations of related nutrients (total and saturated fat, total sugar, potassium, or dietary fiber) that were recommended by the 2010 Dietary Guidelines for Americans for reduced or increased consumption accompanied sodium reduction. The results of sodium reduction efforts, based on resampling of the sentinel foods or re-review of P2Fs, will become available beginning in 2015. This monitoring program tracks sodium reduction efforts, improves food composition databases, and strengthens national nutrition monitoring. © 2015

Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products, Part 3: LED Environmental Testing

Energy Technology Data Exchange (ETDEWEB)

Tuenge, Jason R.; Hollomon, Brad; Dillon, Heather E.; Snowden-Swan, Lesley J.

2013-03-01

This report covers the third part of a larger U.S. Department of Energy (DOE) project to assess the life-cycle environmental and resource impacts in the manufacturing, transport, use, and disposal of light-emitting diode (LED) lighting products in relation to incumbent lighting technologies. All three reports are available on the DOE website (www.ssl.energy.gov/tech_reports.html). • Part 1: Review of the Life-Cycle Energy Consumption of Incandescent, Compact Fluorescent and LED Lamps; • Part 2: LED Manufacturing and Performance; • Part 3: LED Environmental Testing. Parts 1 and 2 were published in February and June 2012, respectively. The Part 1 report included a summary of the life-cycle assessment (LCA) process and methodology, provided a literature review of more than 25 existing LCA studies of various lamp types, and performed a meta-analysis comparing LED lamps with incandescent and compact fluorescent lamps (CFLs). Drawing from the Part 1 findings, Part 2 performed a more detailed assessment of the LED manufacturing process and used these findings to provide a comparative LCA taking into consideration a wider range of environmental impacts. Both reports concluded that the life-cycle environmental impact of a given lamp is dominated by the energy used during lamp operation—the upstream generation of electricity drives the total environmental footprint of the product. However, a more detailed understanding of end-of-life disposal considerations for LED products has become increasingly important as their installation base has grown. The Part 3 study (reported herein) was undertaken to augment the LCA findings with chemical analysis of a variety of LED, CFL, and incandescent lamps using standard testing procedures. A total of 22 samples, representing 11 different models, were tested to determine whether any of 17 elements were present at levels exceeding California or Federal regulatory thresholds for hazardous waste. Key findings include: • The selected

Calculation of harmonic losses and ampacity in low-voltage power cables when used for feeding large LED lighting loads

Directory of Open Access Journals (Sweden)

N. J. Milardovich

2014-10-01

Full Text Available A numerical investigation on the harmonic disturbances in low-voltage cables feeding large LED loads is reported. A frequency domain analysis on several commercially-available LEDs was performed to investigate the signature of the harmonic current injected into the power system. Four-core cables and four single-core cable arrangements (three phases and neutral of small, medium, and large conductor cross sections, with the neutral conductor cross section approximately equal to the half of the phase conductors, were examined. The cables were modelled by using electromagnetic finite-element analysis software. High harmonic power losses (up to 2.5 times the value corresponding to an undistorted current of the same rms value of the first harmonic of the LED current were found. A generalized ampacity model was employed for re-rating the cables. It was found that the cross section of the neutral conductor plays an important role in the derating of the cable ampacity due to the presence of a high-level of triplen harmonics in the distorted current. The ampacity of the cables should be derated by about 40 %, almost independent of the conductor cross sections. The calculation have shown that an incoming widespread use of LED lamps in lighting could create significant additional harmonic losses in the supplying low-voltage lines, and thus more severely harmonic emission limits should be defined for LED lamps.

LED til væksthuse

DEFF Research Database (Denmark)

Dam-Hansen, Carsten; Thorseth, Anders; Rosenqvist, Eva

2012-01-01

Den teknologiske udvikling indenfor Lys Emitterende Dioder (LED) går imod stadig større lysmængder og stadig større effektivitet. Kombineret med fordele som lang levetid, dæmpbarhed og ingen varmestråling gør det, at LED baserede lyskilder/lamper i stigende grad benyttes til belysningsformål og kan...

Integration of organic LEDs with inorganic LEDs for a hybrid lighting system

Science.gov (United States)

Kong, H. J.; Park, J. W.; Kim, Y. M.

2013-01-01

We demonstrate that a surface-emitting hybrid light source can be realized by a combination of organic and inorganic light-emitting devices (LEDs). To this end, a blue inorganic LED bar is deployed at one side of a transparent light guide plate (LGP), and a yellow organic LED (OLED) is in contact with the rear surface of the LGP. In such a configuration, it is found that the overall luminance is almost equivalent to the sum of the luminances measured from each light source, and the overall luminance uniformity is determined mainly by the luminance uniformity of the OLED panel at high luminances. We have achieved a white color showing the Commission Internationale d'Eclairage (CIE) chromaticity coordinates of (x = 0.34, y = 0.33), the power efficiency of 9.3 lm/W, the luminance uniformity of 63% at the luminance of 3100 cd m-2, the color rendering index as high as 89.3, and the correlated color temperature finely tunable within the range between 3000 and 8000 K. Such a system facilitates color tuning by adjusting their luminous intensities and hence the implementation of the emotional lighting system.

Integration of organic LEDs with inorganic LEDs for a hybrid lighting system

International Nuclear Information System (INIS)

Kong, H J; Kim, Y M; Park, J W

2013-01-01

We demonstrate that a surface-emitting hybrid light source can be realized by a combination of organic and inorganic light-emitting devices (LEDs). To this end, a blue inorganic LED bar is deployed at one side of a transparent light guide plate (LGP), and a yellow organic LED (OLED) is in contact with the rear surface of the LGP. In such a configuration, it is found that the overall luminance is almost equivalent to the sum of the luminances measured from each light source, and the overall luminance uniformity is determined mainly by the luminance uniformity of the OLED panel at high luminances. We have achieved a white color showing the Commission Internationale d'Eclairage (CIE) chromaticity coordinates of (x = 0.34, y = 0.33), the power efficiency of 9.3 lm/W, the luminance uniformity of 63% at the luminance of 3100 cd m –2 , the color rendering index as high as 89.3, and the correlated color temperature finely tunable within the range between 3000 and 8000 K. Such a system facilitates color tuning by adjusting their luminous intensities and hence the implementation of the emotional lighting system. (paper)

Peer-led prenatal breast-feeding education: a viable alternative to nurse-led education.

Science.gov (United States)

Rempel, Lynn A; Moore, Katrina C J

2012-02-01

To evaluate a prenatal breast-feeding class developed and facilitated by peer Breast-feeding Buddies. Non-equivalent control group quasi-experimental study comparing participants of the peer-led class (PLC) to those attending an established hospital-based breast-feeding nurse-led class (NLC). A brief questionnaire was completed immediately prior to the class, and telephone interviews were conducted approximately one week following the class, and one and six months post partum. 54 expectant mothers who registered for the community PLC and 55 expectant mothers who registered for the NLC. Breast-feeding intentions were measured at all time-points. Class evaluations, breast-feeding experiences, and breast-feeding support were measured at all post-class interviews. Both classes were considered worthwhile, but the PLC class was rated as more helpful and participants appreciated learning from the peers' personal experiences. Mothers taught by peers were more likely to access peer breast-feeding support. PLC participants initially decreased their prenatal breast-feeding duration intentions but had significantly stronger intentions to continue breast feeding at six months than did NLC mothers. A peer-led prenatal breast-feeding class is as effective as a traditional model of breast-feeding education and is a valuable tool to promote and support successful breast feeding. RECOMMENDATIONS FOR PRACTICE: Peer-led breast-feeding classes should be provided to enhance the accessibility of breast-feeding education and support for expectant mothers. Copyright © 2010 Elsevier Ltd. All rights reserved.

EC-LEDS Supports the Low-Carbon Transition

Energy Technology Data Exchange (ETDEWEB)

2016-09-01

EC-LEDS is a flagship U.S. government-led effort that assists countries to create and implement low emission development strategies, or LEDS -- development frameworks that promote sustainable social and economic development while reducing greenhouse gas emissions over the medium to long term.

LED tests TTO 2010-2011. Focus on energy. Final report; LED Proeven TTO 2010-2011. Focus op energie. Eindverslag

Energy Technology Data Exchange (ETDEWEB)

Peekstok, T.; Duyvesteijn, R.; Persoon, S.; Sanders, J.; De Jong, A. [Tuinbouw Techniek Ontwikkeling TTO, Honselersdijk (Netherlands)

2011-07-15

An overview is given of research results of the application of LED in the horticulture, focusing on high-growing vegetable crops. In this report LED illuminance research for tomatoes is outlined. The project has been carried out from October 2010 to May 2011 in the demonstration nursery Westland. Also, briefly attention is paid to LED lighting tests, performed by TTO (Horticulture Technology Development) in 2008 and 2009 [Dutch] Een overzicht wordt gegeven van de onderzoeksresultaten in de toepassing van LED belichting in de glastuinbouw, met nadruk op hoogopgaande groentegewassen. In dit verslag wordt het onderzoek met LED belichting in tomaat van telersvereniging 'Tuinbouw Techniek Ontwikkeling' (TTO) uiteengezet. Dit project heeft plaatsgevonden vanaf oktober 2010 tot mei 2011 in de Demokwekerij Westland. Hiernaast worden de proeven met LED belichting, welke uitgevoerd zijn door TTO in 2008 en 2009, kort samengevat.

Fokusgruppeinterview som led i en evalueringsproces

DEFF Research Database (Denmark)

Andersen-Mølgaard, Hanna; Harrit, Ole

2006-01-01

Teoretiske begrundelser og perspektiver, responsiv-konstruktivistisk evaluering, fokusgruppeinterview som led i BIKVAmodellen, eksempler, vurdering og perspektivering......Teoretiske begrundelser og perspektiver, responsiv-konstruktivistisk evaluering, fokusgruppeinterview som led i BIKVAmodellen, eksempler, vurdering og perspektivering...

HADRON CALORIMETER (HCAL)

CERN Multimedia

Andris Skuja

HCAL finished commissioning the central and forward detectors during the summer of 2008. HCAL was able to participate in all global runs. In particular, we were anxious to determine the performance of all of the HCAL HPDs at 3.8T. At this point in time this study still has not been completed because of various difficulties CMS has encountered to reach 3.8T. HF Commissioning The HF produces the raw data for the CMS Luminosity determination. It is also an important part of the min-bias trigger and forward jet triggers and physics. In June 2008 the HFs were out of their garages and being worked upon for Castor/Collar platform installation. The HFs were back in the garage position in July and were subject to a series of checks (mainly LED and laser) before starting the CRUZET3 global runs. As part of this sequence, calibration constants were checked via single photo-electrons, the HV choice was finalized and the relative timing was fixed. During CRUZET3 tests of LUMI were performed, and muon signals were measure...

New dental applications with LEDs

DEFF Research Database (Denmark)

Argyraki, A.; Ou, Yiyu; Petersen, Paul Michael

Visible and ultraviolet LEDs will in the future give rise to new dental applications. Fluorescence imaging, photodynamic therapy and photoactivated disinfection are important future candidates for diagnostics and treatment in dentistry.......Visible and ultraviolet LEDs will in the future give rise to new dental applications. Fluorescence imaging, photodynamic therapy and photoactivated disinfection are important future candidates for diagnostics and treatment in dentistry....

Long-lived visible luminescence of UV LEDs and impact on LED excited time-resolved fluorescence applications

International Nuclear Information System (INIS)

Jin, D; Connally, R; Piper, J

2006-01-01

We report the results of a detailed study of the spectral and temporal properties of visible emission from three different GaN-based ultraviolet (UV) light emitting diodes (UV LEDs). The primary UV emission in the 360-380 nm band decays rapidly (less than 1 μs) following switch-off; however, visible luminescence (470-750 nm) with a decay lifetime of tens of microseconds was observed at approximately 10 -4 of the UV intensity. For applications of UV LEDs in time-resolved fluorescence (TRF) employing lanthanide chelates, the visible luminescence from the LEDs competes with the target Eu 3+ or Tb 3+ fluorescence in both spectral and temporal domains. A UV band-pass filter (Schott UG11 glass) was therefore used to reduce the visible luminescence of the UV LEDs by three orders of magnitude relative to UV output to yield a practical excitation source for TRF

Optical characterization of ultrabright LEDs

International Nuclear Information System (INIS)

Benavides, Juan Manuel; Webb, Robert H.

2005-01-01

Ultrabright light emitting diodes (LEDs) are a new light source for visual psychophysics and microscopy. The new LEDs are intended primarily for room and exterior illumination, and the manufacturers' specifications are adequate for that. However, we use them as light sources in situations where a more complete characterization may be useful. For one set of LEDs we have measured the radiometric intensity and its distribution in space and wavelength, and we have tested for interactions of these variables and their dependence on driver configuration. We describe techniques for making these measurements and give a link to a simple calculator for converting among radiometric and photometric measures, as well as an evaluation of the safety considerations these very bright sources demand

White LED visible light communication technology research

Science.gov (United States)

Yang, Chao

2017-03-01

Visible light communication is a new type of wireless optical communication technology. White LED to the success of development, the LED lighting technology is facing a new revolution. Because the LED has high sensitivity, modulation, the advantages of good performance, large transmission power, can make it in light transmission light signal at the same time. Use white LED light-emitting characteristics, on the modulation signals to the visible light transmission, can constitute a LED visible light communication system. We built a small visible optical communication system. The system composition and structure has certain value in the field of practical application, and we also research the key technology of transmitters and receivers, the key problem has been resolved. By studying on the optical and LED the characteristics of a high speed modulation driving circuit and a high sensitive receiving circuit was designed. And information transmission through the single chip microcomputer test, a preliminary verification has realized the data transmission function.

Development of high-performance solar LED lighting system

KAUST Repository

Huang, B.J.; Wu, M.S.; Hsu, P.C.; Chen, J.W.; Chen, K.Y.

2010-01-01

The present study developed a high-performance charge/discharge controller for stand-alone solar LED lighting system by incorporating an nMPPO system design, a PWM battery charge control, and a PWM battery discharge control to directly drive the LED. The MPPT controller can then be removed from the stand-alone solar system and the charged capacity of the battery increases 9.7%. For LED driven by PWM current directly from battery, a reliability test for the light decay of LED lamps was performed continuously for 13,200 h. It has shown that the light decay of PWM-driven LED is the same as that of constant-current driven LED. The switching energy loss of the MOSFET in the PWM battery discharge control is less than 1%. Three solar-powered LED lighting systems (18 W, 100 W and 150 W LED) were designed and built. The long-term outdoor field test results have shown that the system performance is satisfactory with the control system developed in the present study. The loss of load probability for the 18 W solar LED system is 14.1% in winter and zero in summer. For the 100 W solar LED system, the loss of load probability is 3.6% in spring. © 2009 Elsevier Ltd. All rights reserved.

Development of high-performance solar LED lighting system

International Nuclear Information System (INIS)

Huang, B.J.; Wu, M.S.; Hsu, P.C.; Chen, J.W.; Chen, K.Y.

2010-01-01

The present study developed a high-performance charge/discharge controller for stand-alone solar LED lighting system by incorporating an nMPPO system design, a PWM battery charge control, and a PWM battery discharge control to directly drive the LED. The MPPT controller can then be removed from the stand-alone solar system and the charged capacity of the battery increases 9.7%. For LED driven by PWM current directly from battery, a reliability test for the light decay of LED lamps was performed continuously for 13,200 h. It has shown that the light decay of PWM-driven LED is the same as that of constant-current driven LED. The switching energy loss of the MOSFET in the PWM battery discharge control is less than 1%. Three solar-powered LED lighting systems (18 W, 100 W and 150 W LED) were designed and built. The long-term outdoor field test results have shown that the system performance is satisfactory with the control system developed in the present study. The loss of load probability for the 18 W solar LED system is 14.1% in winter and zero in summer. For the 100 W solar LED system, the loss of load probability is 3.6% in spring.

Development of high-performance solar LED lighting system

KAUST Repository

Huang, B.J.

2010-08-01

The present study developed a high-performance charge/discharge controller for stand-alone solar LED lighting system by incorporating an nMPPO system design, a PWM battery charge control, and a PWM battery discharge control to directly drive the LED. The MPPT controller can then be removed from the stand-alone solar system and the charged capacity of the battery increases 9.7%. For LED driven by PWM current directly from battery, a reliability test for the light decay of LED lamps was performed continuously for 13,200 h. It has shown that the light decay of PWM-driven LED is the same as that of constant-current driven LED. The switching energy loss of the MOSFET in the PWM battery discharge control is less than 1%. Three solar-powered LED lighting systems (18 W, 100 W and 150 W LED) were designed and built. The long-term outdoor field test results have shown that the system performance is satisfactory with the control system developed in the present study. The loss of load probability for the 18 W solar LED system is 14.1% in winter and zero in summer. For the 100 W solar LED system, the loss of load probability is 3.6% in spring. © 2009 Elsevier Ltd. All rights reserved.

Evaluating UV-C LED disinfection performance and ...

Science.gov (United States)

This study evaluated ultraviolet (UV) light emitting diodes (LEDs) emitting at 260 nm, 280 nm, and the combination of 260|280 nm together for their efficacy at inactivating Escherichia. coli, MS2 coliphage, human adenovirus type 2 (HAdV2), and Bacillus pumilus spores; research included an evaluation of genomic damage. Inactivation by the LEDs was compared with the efficacy of conventional UV sources, the low-pressure (LP) and medium-pressure (MP) mercury vapor lamps. The work also calculated the electrical energy per order of reduction of the microorganisms by the five UV sources.For E. coli, all five UV sources yielded similar inactivation rates. For MS2 coliphage, the 260 nm LED was most effective. For HAdV2 and B. pumilus, the MP UV lamp was significantly more effective than the LP UV and UVC LED sources. When considering electrical energy per order of reduction, the LP UV lamp was the most efficient for E. coli and MS2, and the MPUV and LPUV were equally efficient for HAdV2 and B. pumilus spores. Among the UVC LEDs, the 280 nm LED unit required the least energy per log reduction of E. coli and HAdV2. The 280 nm and 260|280 nm LED units were equally efficient per log reduction of B. pumilus spores, and the 260 nm LED unit required the lowest energy per order of reduction of MS2 coliphage. The combination of the 260 nm and 280 nm UV LED wavelengths was also evaluated for potential synergistic effects. No dual-wavelength synergy was detected for inactivation of

ZnO-nanorods: A possible white LED phosphor

Science.gov (United States)

Sarangi, Sachindra Nath; T., Arun; Ray, Dinseh K.; Sahoo, Pratap Kumar; Nozaki, Shinji; Sugiyama, Noriyuki; Uchida, Kazuo

2017-05-01

The white light-emitting diodes (LEDs) have drawn much attention to replace conventional lighting sources because of low energy consumption, high light efficiency and long lifetime. Although the most common approach to produce white light is to combine a blue LED chip and a yellow phosphor, such a white LED cannot be used for a general lighting application, which requires a broad luminescence spectrum in the visible wavelength range. We have successfully chemically synthesized the ZnO nanorods showing intense broad luminescence in the visible wavelength range and made a white LED using the ZnO nanorods as phosphor excited with a blue LED. Their lengths and diameters were 2 - 10 μm and 200 - 800 nm, respectively. The wurtzite structure was confirmed by the x-ray diffraction measurement. The PL spectrum obtained by exciting the ZnO nanorods with the He-Cd laser has two peaks, one associated with the near band-edge recombination and the other with recombination via defects. The peak intensity of the near band-edge luminescence at 388 nm is much weaker than that of the defect-related luminescence. The latter luminescence peak ranges from 450 to 850 nm and broad enough to be used as a phosphor for a white LED. A white LED has been fabricated using a blue LED with 450 nm emission and ZnO nanorod powders. The LED performances show a white light emission and the electroluminescence measurement shows a stiff increase in white light intensity with increasing blue LED current. The Commission International de1'Eclairage (CIE) chromaticity colour coordinates of 450 nm LED pumped white emission shows a coordinate of (0.31, 0.32) for white LED at 350 mA. These results indicate that ZnO nanorods provides an alternate and effective approach to achieve high-performance white LEDs and also other optoelectronic devices.

LED Virtual Simulation based on Web3D

OpenAIRE

Lilan Liu; Liu Han; Zhiqi Lin; Manping Li; Tao Yu

2014-01-01

Regarding to the high price and low market popularity of current LED indoor lighting products, a LED indoor lighting platform is proposed based on Web3D technology. The internet virtual reality technology is integrated and applied into the LED collaborative e-commerce website with Virtools. According to the characteristics of the LED indoor lighting products, this paper introduced the method to build encapsulated model and three characteristics of LED lighting: geometrical, optical and behavi...

Practical lighting design with LEDs

CERN Document Server

Lenk, Ron

2016-01-01

The second edition of Practical Lighting Design with LEDs has been revised and updated to provide the most current information for developing light-emitting diodes products. The authors, noted authorities in the field, offer a review of the most relevant topics including optical performance, materials, thermal design, and modeling and measurement. Comprehensive in scope, the text covers all the information needed to design LEDs into end products.

UV-LED Curing Efficiency of Wood Coatings

OpenAIRE

Véronic Landry; Pierre Blanchet; Gabrielle Boivin; Jean-François Bouffard; Mirela Vlad

2015-01-01

Ultraviolet light emitting diodes (UV-LEDs) have attracted great interest in recent years. They can be used to polymerize coatings, such as those used for prefinished wood flooring. In this project, two lamps were compared for their suitability to be used on a wood flooring finishing line: a UV-microwave and a UV-LED lamp. Low heat emission was found for the UV-LED lamp compared to the UV-microwave one. This study also reveals that the 4 W/cm2 UV-LED lamp used is not powerf...

Led Zeppelin reklaamib Narvat / Anti Ronk

Index Scriptorium Estoniae

Ronk, Anti

2007-01-01

Ilmus Narva-teemaline kahest CD-st koosnev album, kus ühel plaadil on 60 minutit videot linna vaatamisväärsuste ja informatsiooniga, teisel - briti rockansambli Led Zeppelini teosed Narva sümfooniaorkestri ja rockansambli Led R esituses

Commercial lumber

Science.gov (United States)

Kent A. McDonald; David E. Kretschmann

1999-01-01

In a broad sense, commercial lumber is any lumber that is bought or sold in the normal channels of commerce. Commercial lumber may be found in a variety of forms, species, and types, and in various commercial establishments, both wholesale and retail. Most commercial lumber is graded by standardized rules that make purchasing more or less uniform throughout the country...

Advanced Cardiac Resuscitation Evaluation (ACRE: A randomised single-blind controlled trial of peer-led vs. expert-led advanced resuscitation training

Directory of Open Access Journals (Sweden)

Hughes Thomas C

2010-01-01

Full Text Available Abstract Background Advanced resuscitation skills training is an important and enjoyable part of medical training, but requires small group instruction to ensure active participation of all students. Increases in student numbers have made this increasingly difficult to achieve. Methods A single-blind randomised controlled trial of peer-led vs. expert-led resuscitation training was performed using a group of sixth-year medical students as peer instructors. The expert instructors were a senior and a middle grade doctor, and a nurse who is an Advanced Life Support (ALS Instructor. A power calculation showed that the trial would have a greater than 90% chance of rejecting the null hypothesis (that expert-led groups performed 20% better than peer-led groups if that were the true situation. Secondary outcome measures were the proportion of High Pass grades in each groups and safety incidents. The peer instructors designed and delivered their own course material. To ensure safety, the peer-led groups used modified defibrillators that could deliver only low-energy shocks. Blinded assessment was conducted using an Objective Structured Clinical Examination (OSCE. The checklist items were based on International Liaison Committee on Resuscitation (ILCOR guidelines using Ebel standard-setting methods that emphasised patient and staff safety and clinical effectiveness. The results were analysed using Exact methods, chi-squared and t-test. Results A total of 132 students were randomised: 58 into the expert-led group, 74 into the peer-led group. 57/58 (98% of students from the expert-led group achieved a Pass compared to 72/74 (97% from the peer-led group: Exact statistics confirmed that it was very unlikely (p = 0.0001 that the expert-led group was 20% better than the peer-led group. There were no safety incidents, and High Pass grades were achieved by 64 (49% of students: 33/58 (57% from the expert-led group, 31/74 (42% from the peer-led group. Exact

The WIMSE-E module W-LED

International Nuclear Information System (INIS)

Roth, M.J.

1992-06-01

This report describes the WIMS-E edit module W-LED. W-LED sets up a library of cross section and other nuclear data for a set of materials for subsequent use in a whole reactor program such as PANTHER. (author)

19 CFR 113.67 - Commercial gauger and commercial laboratory bond conditions.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Commercial gauger and commercial laboratory bond... SECURITY; DEPARTMENT OF THE TREASURY CUSTOMS BONDS Customs Bond Conditions § 113.67 Commercial gauger and commercial laboratory bond conditions. Commercial Gauger Bond Conditions (a) Commercial gauger bond...

A systems approach to the commercialization of space communications technology - The NASA/JPL Mobile Satellite Program

Science.gov (United States)

Weber, William J., III; Gray, Valerie W.; Jackson, Byron; Steele, Laura C.

1991-10-01

This paper discusss the systems approach taken by NASA and the Jet Propulsion Laboratory in the commercialization of land-mobile satellite services (LMSS) in the United States. As the lead center for NASA's Mobile Satellite Program, JPL was involved in identifying and addressing many of the key barriers to commercialization of mobile satellite communications, including technical, economic, regulatory and institutional risks, or uncertainties. The systems engineering approach described here was used to mitigate these risks. The result was the development and implementation of the JPL Mobile Satellite Experiment Project. This Project included not only technology development, but also studies to support NASA in the definition of the regulatory, market, and investment environments within which LMSS would evolve and eventually operate, as well as initiatives to mitigate their associated commercialization risks. The end result of these government-led endeavors was the acceleration of the introduction of commercial mobile satellite services, both nationally and internationally.

Rationalization and Internal Control: Improving Marine Corps Unit-Level Internal Management Controls for the Government-Wide Commercial Purchase Card Program

National Research Council Canada - National Science Library

Wood, Lewis

2003-01-01

... Commercial Purchase Card (GCPC) Program for the first half of fiscal year (FY) 2003, led the author of this article to review GCPC usage in the Marine Corps as the basis for a Naval Postgraduate School Master of Business Administration thesis...

Public Intentions for Private Spaces: Exploring Architects’ Tactics to Shape Shared Space in Private-Led Residential Development

Directory of Open Access Journals (Sweden)

Saul Manuel Golden

2015-07-01

Full Text Available From the late 20th into the 21st centuries, the private market increasingly gained control from public authorities over strategic decisions affecting the quality of, and accessibility to, new urban development. This paper argues for architects to act more explicitly to promote greater open-ness and use-value, rather than more objectified and controlled exchange-value approaches to the public domain in private-led development. The paper analyses two London-based residential case studies and interviews with the architects about perceptions of, and approaches to, private-led development decision-making processes. It compares the individual practitioner’s experiences of architecture practice with explicit intentions to influence better quality shared city space, examining professional norms vis-à-vis commercial clients and wider society. The paper concludes that greater awareness of architects’ knowledge, skills, and a range of tactics to influence future shared environments can contribute to improved professional practice frameworks for more effective engagement in an increasingly globalised and privatised urban society.

Preliminary Evaluation Of Commercial Supercapacitors For Space Applications

Science.gov (United States)

Gineste, Valery; Loup, Didier; Mattesco, Patrick; Neugnot, Nicolas

2011-10-01

Supercapacitors are identified since years as a new technology enabling energy storage together with high power delivery capability to the system. A recent ESA study [1] led by Astrium has demonstrated the interest of these devices for space application, providing that reliability and end of life performances are demonstrated. A realistic commercial on the shelf (COTS) approach (or with limited design modification approved by potential suppliers) has been favoured (as for batteries). This paper presents preliminary test results done by Astrium on COTS supercapacitors: accelerated life tests, calendar life tests, technology analyses. Based on these results, assessment and lessons learnt are drawn in view of future exhaustive supercapacitor validation and future qualification.

High Efficiency Driving Electronics for General Illumination LED Luminaires

Energy Technology Data Exchange (ETDEWEB)

Upadhyay, Anand

2012-10-31

New generation of standalone LED driver platforms developed, which are more efficient These LED Drivers are more efficient (≥90%), smaller in size ( 0.15 in3/watt), lower in cost ( 12 cents/watt in high volumes in millions of units). And these products are very reliable having an operating life of over 50,000 hours. This technology will enable growth of LED light sources in the use. This will also help in energy saving and reducing total life cycle cost of LED units. Two topologies selected for next generation of LED drivers: 1) Value engineered single stage Flyback topology. This is suitable for low powered LED drivers up to 50W power. 2) Two stage boost power factor correction (PFC) plus LLC half bridge platform for higher powers. This topology is suitable for 40W to 300W LED drivers. Three new product platforms were developed to cover a wide range of LED drivers: 1) 120V 40W LED driver, 2) Intellivolt 75W LED driver, & 3) Intellivolt 150W LED driver. These are standalone LED drivers for rugged outdoor lighting applications. Based on these platforms number of products are developed and successfully introduced in the market place meeting key performance, size and cost goals.

LED system reliability

NARCIS (Netherlands)

Driel, W.D. van; Yuan, C.A.; Koh, S.; Zhang, G.Q.

2011-01-01

This paper presents our effort to predict the system reliability of Solid State Lighting (SSL) applications. A SSL system is composed of a LED engine with micro-electronic driver(s) that supplies power to the optic design. Knowledge of system level reliability is not only a challenging scientific

LED-pumped Alexandrite laser oscillator and amplifier

Science.gov (United States)

Pichon, Pierre; Blanchot, Jean-Philippe; Balembois, François; Druon, Frédéric; Georges, Patrick

2018-02-01

In this paper, we report the first LED-pumped transition-metal-doped laser oscillator and amplifier based on an alexandrite crystal (Cr3+:BeAl2O4). A Ce:YAG luminescent concentrator illuminated by blue LEDs is used to reach higher pump powers than with LEDs alone. The luminescent 200-mm-long-composit luminescent concentrator involving 2240 LEDs can delivers up to 268 mJ for a peak irradiance of 8.5 kW/cm2. In oscillator configuration, an LED-pumped alexandrite laser delivering an energy of 2.9 mJ at 748 nm in free running operation is demonstrated. In the cavity, we measured a double pass small signal gain of 1.28, in good agreement with numerical simulations. As amplifier, the system demonstrated to boost a CW Ti:sapphire laser by a factor of 4 at 750 nm in 8 passes with a large tuning range from 710 nm to 800 nm.

Patient-led versus physician-led titration of insulin glargine in patients with uncontrolled type 2 diabetes: a randomized multinational ATLAS study.

Science.gov (United States)

Garg, Satish K; Admane, Karim; Freemantle, Nick; Odawara, Masato; Pan, Chang-Yu; Misra, Anoop; Jarek-Martynowa, Iwona R; Abbas-Raza, Syed; Mirasol, Roberto C; Perfetti, Riccardo

2015-02-01

Self-adjustment of insulin dose is commonly practiced in Western patients with type 2 diabetes but is usually not performed in Asian patients. This multinational, 24-week, randomized study compared patient-led with physician-led titration of once-daily insulin glargine in Asian patients with uncontrolled type 2 diabetes who were on 2 oral glucose-lowering agents. Patient-led (n = 275) or physician-led (n = 277) subjects followed the same dose-titration algorithm guided by self-monitored fasting blood glucose (FBG; target, 110 mg/dL [6.1 mmol/L]). The primary endpoint was change in mean glycated hemoglobin (HbA1c) at week 24 in the patient-led versus physician-led titration groups. Patient-led titration resulted in a significantly higher drop in HbA1c value at 24 weeks when compared with physician-led titration (-1.40% vs. -1.25%; mean difference, -0.15; 95% confidence interval, -0.29 to 0.00; P = .043). Mean decrease in FBG was greatest in the patient-led group (-2.85 mmol/L vs. -2.48 mmol/L; P = .001). The improvements in HbA1c and FBG were consistent across countries, with similar improvements in treatment satisfaction in both groups. Mean daily insulin dose was higher in the patient-led group (28.9 units vs. 22.2 units; Ptitration achieved near-target blood glucose levels in Asian patients with uncontrolled type 2 diabetes who were on 2 oral glucose-lowering drugs, demonstrating that Asian patients can self-uptitrate insulin dose effectively when guided.

Open LED Illuminator: A Simple and Inexpensive LED Illuminator for Fast Multicolor Particle Tracking in Neurons

Science.gov (United States)

Bosse, Jens B.; Tanneti, Nikhila S.; Hogue, Ian B.; Enquist, Lynn W.

2015-01-01

Dual-color live cell fluorescence microscopy of fast intracellular trafficking processes, such as axonal transport, requires rapid switching of illumination channels. Typical broad-spectrum sources necessitate the use of mechanical filter switching, which introduces delays between acquisition of different fluorescence channels, impeding the interpretation and quantification of highly dynamic processes. Light Emitting Diodes (LEDs), however, allow modulation of excitation light in microseconds. Here we provide a step-by-step protocol to enable any scientist to build a research-grade LED illuminator for live cell microscopy, even without prior experience with electronics or optics. We quantify and compare components, discuss our design considerations, and demonstrate the performance of our LED illuminator by imaging axonal transport of herpes virus particles with high temporal resolution. PMID:26600461

Open LED Illuminator: A Simple and Inexpensive LED Illuminator for Fast Multicolor Particle Tracking in Neurons.

Directory of Open Access Journals (Sweden)

Jens B Bosse

Full Text Available Dual-color live cell fluorescence microscopy of fast intracellular trafficking processes, such as axonal transport, requires rapid switching of illumination channels. Typical broad-spectrum sources necessitate the use of mechanical filter switching, which introduces delays between acquisition of different fluorescence channels, impeding the interpretation and quantification of highly dynamic processes. Light Emitting Diodes (LEDs, however, allow modulation of excitation light in microseconds. Here we provide a step-by-step protocol to enable any scientist to build a research-grade LED illuminator for live cell microscopy, even without prior experience with electronics or optics. We quantify and compare components, discuss our design considerations, and demonstrate the performance of our LED illuminator by imaging axonal transport of herpes virus particles with high temporal resolution.

Estimating the supply and demand for commercial heavy truck parking on interstate highways : a case study of I-81 in Virginia.

Science.gov (United States)

2002-01-01

The increasing number of trucks traveling on Virginia highways has led to a growing demand for public rest areas and private truck stops. This study developed a methodology to determine the supply and demand for commercial heavy truck parking using I...

Energy savings by implementation of light quality LED lighting. Final report; Implementering af energibesparelser ved benyttelse af hoejkvalitets LED belysning. Slutrapport

Energy Technology Data Exchange (ETDEWEB)

Dam-Hansen, C.; Thorseth, A.; Poulsen, Peter

2010-03-15

The project developed two new LED light sources and systems, emphasising the potential of LED technology for energy savings and lighting quality. A LED light source for display case lighting, replacing incandescent lamps, was successfully installed in the Treasury at Rosenborg Castle in Copenhagen, Denmark, and it was decided to extend the solution in 2010. Electricity savings of 74% were achieved. LED light sources replacing halogen bulbs in cooker hoods reduce electricity consumption by 69% and ensure even lighting of the entire working surface with about 500 lux at all cooking areas. Furthermore, a new LED optics system was patented. (ln)

An overview of LED applications for general illumination

Science.gov (United States)

Pelka, David G.; Patel, Kavita

2003-11-01

This paper begins by reviewing the current state of development of LEDs, their existing markets as well as their potential for energy conservation and their potential for gaining market share in the general illumination market. It discusses LED metrics such as chip size, lumens per watt, thermal resistance, and the recommended maximum current rating. The paper then goes on to consider the importance of non-imaging optics for both optically efficient and extremely compact LED lighting systems. Finally, microstructures useful for controlling the fields-of-view of LED lighting systems are considered and described in some detail. An extremely efficient and cost effective microstructure, called kinoform diffusers, is shown to have very unique properties that make this technology almost ideal for shaping the output beams of LED lighting systems. It concludes by illustrating some general illumination LED lighting systems

Space Commercialization

Science.gov (United States)

Martin, Gary L.

2011-01-01

A robust and competitive commercial space sector is vital to continued progress in space. The United States is committed to encouraging and facilitating the growth of a U.S. commercial space sector that supports U.S. needs, is globally competitive, and advances U.S. leadership in the generation of new markets and innovation-driven entrepreneurship. Energize competitive domestic industries to participate in global markets and advance the development of: satellite manufacturing; satellite-based services; space launch; terrestrial applications; and increased entrepreneurship. Purchase and use commercial space capabilities and services to the maximum practical extent Actively explore the use of inventive, nontraditional arrangements for acquiring commercial space goods and services to meet United States Government requirements, including measures such as public-private partnerships, . Refrain from conducting United States Government space activities that preclude, discourage, or compete with U.S. commercial space activities. Pursue potential opportunities for transferring routine, operational space functions to the commercial space sector where beneficial and cost-effective.

Hydroponics or soilless culture

Science.gov (United States)

Chapman, H. D.

1963-01-01

Historically, hydroponics is not a new field; plant physiologists have known and used it for some 100 years. Inevitably, some enthusiasts got carried away.Claims were made of enormous potential yields; skyscraper tops were said to be capable of producing enough food for all of their occupants; and closets, basements, garages, etc. were wishfully converted into fields for hydroponic culture. Numerous publications on the subject appeared during this period. Basic requirements for hydropinc techniques are given along with examples of where soilless culture has been used commercially.

Evaluation of a pilot police-led suicide early alert surveillance strategy in the UK.

Science.gov (United States)

McGeechan, Grant James; Richardson, Catherine; Weir, Kevin; Wilson, Lynn; O'Neill, Gillian; Newbury-Birch, Dorothy

2017-07-19

Those bereaved by suicide are at increased risk of psychological harm, which can be reduced with the provision of timely support. This paper outlines an evaluation of a pilot police-led suicide strategy, in comparison to a coroner-led suicide strategy looking at the number, and length of time it takes for deaths to be recorded for each strategy. Additionally, the police-led strategy offers timely contact from support services for bereaved individuals. We examined what impact this offer of support had on the capacity of support services. A mixed methods evaluation compared how long it took for suspected suicides to be recorded using both strategies. The number of referrals received by support services during the pilot strategy were compared with those from previous years. A feedback focus group, and interviews, were held with key stakeholders. The coroner strategy was more consistent at identifying suspected suicides; however, reports were filed quicker by the police. Bereaved individuals were willing to share contact details with police officers and consent for referral to support services which lead to increased referrals. The focus group and interviews revealed that the pilot police strategy needs better integration into routine police practice. This strategy has the potential to deliver a real benefit to those bereaved by suicide; however, there are still aspects which could be improved. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Semiconductor lasers and herterojunction leds

CERN Document Server

Kressel, Henry

2012-01-01

Semiconductor Lasers and Heterojunction LEDs presents an introduction to the subject of semiconductor lasers and heterojunction LEDs. The book reviews relevant basic solid-state and electromagnetic principles; the relevant concepts in solid state physics; and the p-n junctions and heterojunctions. The text also describes stimulated emission and gain; the relevant concepts in electromagnetic field theory; and the modes in laser structures. The relation between electrical and optical properties of laser diodes; epitaxial technology; binary III-V compounds; and diode fabrication are also consider

'No blue' LED solution for photolithography room illumination

DEFF Research Database (Denmark)

Ou, Haiyan; Corell, Dennis Dan; Dam-Hansen, Carsten

2010-01-01

This paper explored the feasibility of using a LED-based bulb as the illumination light source for photolithography room. A no-blue LED was designed, and the prototype was fabricated. The spectral power distribution of both the LED bulb and the yellow fluorescent tube was measured. Based on that...... color rendering ability than the YFT. Furthermore, LED solution has design flexibility to improve it further. The prototype has been tested with photoresist SU8-2005. Even after 15 days of illumination, no effect was observed. So this LED-based solution was demonstrated to be a very promising light......, colorimetric values were calculated and compared on terms of chromatic coordinates, correlated color temperature, color rendering index, and chromatic deviation. Gretagmacbeth color charts were used as a more visional way to compare the two light sources, which shows that our no-blue LED bulb has much better...

Designing low cost LED display for the billboard

Science.gov (United States)

Hong, Yi-Jian; Uang, Chii-Maw; Wang, Ping-Chieh; Ho, Zu-Sheng

2011-10-01

With quickly advance of the computer, microelectronics and photonics technologies, LED display panel becomes a new electronic advertising media. It can be used to show any information whatever characters or graphics. Most LED display panels are built of many Light-Emitting Diodes arranged in a matrix form. The display has many advantages such as low power, low cost, long life and high definition. Because the display panel is asked to show rich color, the LED display panel's driving system becomes very complex. The design methodology of LED display panel's driver becomes more and more important to meet the market requirements. Cost is always the most important issue in public market domain. In this paper, we report a design methodology of LED display panel's driver based on the microprocessor control unit (MCU) system and LED display controller IC, HT1632C, to control three colors, RGB, color LED display panel and the modular panel size is 24*16 in matrix form. The HT1632C is a memory mapping LED display controller, it can be used on many applications, such as digital clock, thermometer, counter, voltmeter or other instrumentation readouts. Three pieces of HT1632C are used to drive a 24*16 RGB LED display panel, in our design case. Each HT163C chip is used to control one of the R, G and B color. As the drive mode is driven in DC mode, the RGB display panel can create and totally of seven colors under the control of MCU. The MCU generates the control signal to drive HT1632C. In this study, the software design methodology is adopted with dynamic display principle. When the scan frequency is 60Hz, LED display panel will get the clear picture and be able to display seven colors.

The LED monitoring system of the PHOENICS experiment

International Nuclear Information System (INIS)

Urban, D.

1991-07-01

The PHOENICS experiment at ELSA uses a LED monitoring system to control pulse height and time measurement with scintillation counters. A green LED is mounted at the light guide of each of the 304 involved photomultiplier tubes. The LEDs are driven by fast voltage pulses of 5 ns FWHM width and about 20 V amplitude. Simulation of single events is possible by computer controlled switching of individual LEDs. In order to correct for the temperature dependence of the LED intensity an automatic temperature recording system was coupled to the computer. This monitor system allows to control the pulse height and time measurement with an accuracy of about 2% and 100 ps respectively. (orig.) [de

Modelling intelligence-led policing to identify its potential

NARCIS (Netherlands)

Hengst-Bruggeling, M. den; Graaf, H.A.L.M. de; Scheepstal, P.G.M. van

2014-01-01

lntelligence-led policing is a concept of policing that has been applied throughout the world. Despite some encouraging reports, the effect of intelligence-led policing is largely unknown. This paper presents a method with which it is possible to identify intelligence-led policing's potential to

White LEDs as broad spectrum light sources for spectrophotometry: demonstration in the visible spectrum range in a diode-array spectrophotometric detector.

Science.gov (United States)

Piasecki, Tomasz; Breadmore, Michael C; Macka, Mirek

2010-11-01

Although traditional lamps, such as deuterium lamps, are suitable for bench-top instrumentation, their compatibility with the requirements of modern miniaturized instrumentation is limited. This study investigates the option of utilizing solid-state light source technology, namely white LEDs, as a broad band spectrum source for spectrophotometry. Several white light LEDs of both RGB and white phosphorus have been characterized in terms of their emission spectra and energy output and a white phosphorus Luxeon LED was then chosen for demonstration as a light source for visible-spectrum spectrophotometry conducted in CE. The Luxeon LED was fixed onto the base of a dismounted deuterium (D(2) ) lamp so that the light-emitting spot was geometrically positioned exactly where the light-emitting spot of the original D(2) lamp is placed. In this manner, the detector of a commercial CE instrument equipped with a DAD was not modified in any way. As the detector hardware and electronics remained the same, the change of the deuterium lamp for the Luxeon white LED allowed a direct comparison of their performances. Several anionic dyes as model analytes with absorption maxima between 450 and 600 nm were separated by CE in an electrolyte of 0.01 mol/L sodium tetraborate. The absorbance baseline noise as the key parameter was 5 × lower for the white LED lamp, showing clearly superior performance to the deuterium lamp in the available, i.e. visible part of the spectrum. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

UV-LED Curing Efficiency of Wood Coatings

Directory of Open Access Journals (Sweden)

Véronic Landry

2015-12-01

Full Text Available Ultraviolet light emitting diodes (UV-LEDs have attracted great interest in recent years. They can be used to polymerize coatings, such as those used for prefinished wood flooring. In this project, two lamps were compared for their suitability to be used on a wood flooring finishing line: a UV-microwave and a UV-LED lamp. Low heat emission was found for the UV-LED lamp compared to the UV-microwave one. This study also reveals that the 4 W/cm2 UV-LED lamp used is not powerful enough to cure UV high solids acrylate coatings while satisfactory results can be obtained for UV water-based formulations. In fact, conversion percentages were found to be low for the high solids coatings, leaving the coatings tacky. Higher conversion percentages were obtained for the UV water-based formulations. As a result, mass loss, hardness, and scratch resistance found for the samples cured by UV-LED were closed to the ones found for the samples cured using the UV microwave lamp.

Design methodologies for reliability of SSL LED boards

NARCIS (Netherlands)

Jakovenko, J.; Formánek, J.; Perpiñà, X.; Jorda, X.; Vellvehi, M.; Werkhoven, R.J.; Husák, M.; Kunen, J.M.G.; Bancken, P.; Bolt, P.J.; Gasse, A.

2013-01-01

This work presents a comparison of various LED board technologies from thermal, mechanical and reliability point of view provided by an accurate 3-D modelling. LED boards are proposed as a possible technology replacement of FR4 LED boards used in 400 lumen retrofit SSL lamps. Presented design

Test results and commercialization plans for long life Stirling generators

International Nuclear Information System (INIS)

Erbeznik, R.M.; White, M.A.

1996-01-01

Many optimistic predictions regarding commercialization of Stirling engines have been announced over the years, but to date no real successes have emerged. STC is excited to announce the availability of beta prototypes for its RemoteGen trademark family of free-piston Stirling generators. STC is working with suppliers, manufacturers, and beta customers to commercialize the RemoteGen family of generators. STC is proving that these machines overcome previously inhibiting barriers by providing long life, high reliability, cost effective mass production, and market relevance. Stirling power generators are generally acknowledged to offer much higher conversion efficiencies than direct energy conversion systems. Life and reliability, on the other hand, are generally considered superior for direct conversion systems, as established by the exceptional endurance records (though with degradation) for thermoelectric (TE) and photovoltaic (PV) systems. STC's unique approaches combine dynamic system efficiency with static system reliability. The RemoteGen family presently includes a 10-watt RG-10, a 350-watt RG-350, and with 1-kW and 3-kW sizes planned for the future. They all use the same basic configuration with flexure bearings, clearance seals, and moving iron linear alternators. The third generation RG-10 has entered limited production with a radioisotope-fueled version, and a niche market for a propane-fueled version has been identified. Market analysis has led STC to focus on early commercial production of the RG-350. The linear alternator power module portion of the RG-350 is also used in its sister BeCool trademark family of coolers as the linear motor. By using a common power module, both programs will benefit by each other's commercialization efforts. The technology behind the RemoteGen generators, test results, and plans for commercialization are described in this paper

77 FR 30919 - Commercial Driver's License Testing and Commercial Learner's Permit Standards

Science.gov (United States)

2012-05-24

..., and 385 [Docket No. FMCSA-2007-27659] Commercial Driver's License Testing and Commercial Learner's... published a final rule titled ``Commercial Driver's License Testing and Commercial Learner's Permit... additional drivers, primarily those transporting certain tanks temporarily attached to the commercial motor...

High power blue LED development using different growth modes

Energy Technology Data Exchange (ETDEWEB)

Lee, Dong S.; Florescu, Doru I.; Ramer, Jeff C.; Merai, Vinod; Parekh, Aniruddh; Begarney, Michael J.; Armour, Eric A. [Veeco TurboDisc Operations, 394 Elizabeth Avenue, Somerset, NJ 08873 (United States); Lu Dong [Veeco TurboDisc Operations, 394 Elizabeth Avenue, Somerset, NJ 08873 (United States); School of Engineering, Rutgers University, Piscataway, NJ 08854 (United States)

2004-09-01

Blue high brightness light emitting diodes (HB-LEDs) have been developed using different growth modes in the active layers. Piezoelectric field engineering improves the optical output power in multiple quantum well (MQW) LEDs by inserting an optimized transitional superlattice (TSL) before the active MQW layers. Within single quantum well (SQW) LEDs, quasi-Quantum Dot (QD) growth for Indium localization has been realized. The SQW LED output power exceeds the strain engineered MQW LEDs. The experimental data indicates that Indium localization enhances overall quantum efficiency and results in increased output power for HB-LEDs. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Preliminary investigations of piezoelectric based LED luminary

DEFF Research Database (Denmark)

Nielsen, Dennis; Andersen, Michael A. E.; Meyer, Kaspar Sinding

2011-01-01

, modulation schemes, LEDs and LED driving conditions are analyzed. A prototype radial mode PT optimized for ZVS (Zero Voltage Switching) is designed. FEM (Final Element Method) and measurements validates the PT design. A prototype PT based AC/DC converter operating from european mains is proposed......This paper presents a preliminary study of PT (Piezoelectric Transformer) based SMPS’s (Switch Mode Power Supplies) for LED luminary. The unique properties of PTs (efficiency, power density and EMI) make them highly suitable for this application. Power stage topologies, rectifiers circuits...

Colour differences in Caucasian and Oriental women's faces illuminated by white LED sources.

Science.gov (United States)

Melgosa, M; Richard, N; Fernández-Maloigne, C; Xiao, K; de Clermont-Gallerande, H; Jost-Boissard, S; Okajima, K

2018-04-10

To provide an approach to facial contrast, analysing CIELAB colour differences (ΔE* ab,10 ) and its components in women's faces from two different ethnic groups, illuminated by modern white light-emitting diodes (LEDs) or traditional illuminants recommended by the International Commission on Illumination (CIE). We performed spectrophotometric measurements of spectral reflectance factors on forehead and cheek of 87 young healthy women (50 Caucasians and 37 Orientals), plus 5 commercial red lipsticks. We considered a set of 10 white LED illuminants, representative of technologies currently available on the market, plus 8 main illuminants currently recommended by the CIE, representative of conventional incandescent, daylight, and fluorescent light sources. Under each of these 18 illuminants we analysed the magnitude and components of ΔE* ab,10 between Caucasian and Oriental women (considering cheek and forehead), as well as for cheek-forehead and cheek-lipsticks in Caucasian and Oriental women. Colour-inconstancy indices for cheek, forehead, and lipsticks were computed, assuming D65 and A as reference illuminants. ΔE* ab,10 between forehead and cheek were quantitatively and qualitatively different in Orientals and Caucasians, but discrepancies with respect to average values for 18 illuminants were small (1.5% and 5.0% for Orientals and Caucasians, respectively). ΔE* ab,10 between Caucasians and Orientals were also quantitatively and qualitatively different both for forehead and cheek, and discrepancies with respect to average values were again small (1.0% and 3.9% for forehead and cheek, respectively). ΔE* ab,10 between lipsticks and cheek were at least 2 times higher than those between forehead and cheek. Regarding ΔE* ab,10 between lipsticks and cheeks, discrepancies with respect to average values were in the range 1.5% - 12.3%, although higher values of up to 54.2% were found for a white RGB LED. This white RGB LED provided the highest average colour

GaN-on-Si blue/white LEDs: epitaxy, chip, and package

Science.gov (United States)

Qian, Sun; Wei, Yan; Meixin, Feng; Zengcheng, Li; Bo, Feng; Hanmin, Zhao; Hui, Yang

2016-04-01

The dream of epitaxially integrating III-nitride semiconductors on large diameter silicon is being fulfilled through the joint R&D efforts of academia and industry, which is driven by the great potential of GaN-on-silicon technology in improving the efficiency yet at a much reduced manufacturing cost for solid state lighting and power electronics. It is very challenging to grow high quality GaN on Si substrates because of the huge mismatch in the coefficient of thermal expansion (CTE) and the large mismatch in lattice constant between GaN and silicon, often causing a micro-crack network and a high density of threading dislocations (TDs) in the GaN film. Al-composition graded AlGaN/AlN buffer layers have been utilized to not only build up a compressive strain during the high temperature growth for compensating the tensile stress generated during the cool down, but also filter out the TDs to achieve crack-free high-quality n-GaN film on Si substrates, with an X-ray rocking curve linewidth below 300 arcsec for both (0002) and (101¯2) diffractions. Upon the GaN-on-Si templates, prior to the deposition of p-AlGaN and p-GaN layers, high quality InGaN/GaN multiple quantum wells (MQWs) are overgrown with well-engineered V-defects intentionally incorporated to shield the TDs as non-radiative recombination centers and to enhance the hole injection into the MQWs through the via-like structures. The as-grown GaN-on-Si LED wafers are processed into vertical structure thin film LED chips with a reflective p-electrode and the N-face surface roughened after the removal of the epitaxial Si(111) substrates, to enhance the light extraction efficiency. We have commercialized GaN-on-Si LEDs with an average efficacy of 150-160 lm/W for 1mm2 LED chips at an injection current of 350 mA, which have passed the 10000-h LM80 reliability test. The as-produced GaN-on-Si LEDs featured with a single-side uniform emission and a nearly Lambertian distribution can adopt the wafer-level phosphor

Refrigerating liquid prototype for LED's thermal management

International Nuclear Information System (INIS)

Faranda, Roberto; Guzzetti, Stefania; Lazaroiu, George Cristian; Leva, Sonia

2012-01-01

The heat management is the critical factor for high performance operation of LED. A new heat management application of refrigerating liquid integrated within a fabricated prototype is proposed and investigated. A series of experiments considering different heights of liquid level were performed to evaluate the heat dissipation performance and optical characteristics of the refrigerating liquid based prototype. The results reveal that the junction temperature decreases as the level of refrigerating liquid increases. The experimental results report that the refrigerating liquid reduces the junction temperature, and can positively influence the luminous radiation performances. An optimization investigation of the proposed solution was carried out to find an optimum thermal performance. The experiments indicated that refrigerating liquid cooling is a powerful way for heat dissipation of high power LEDs, and the fabrication of prototype was feasible and useful. - Highlights: ► New heat management application of refrigerating liquid on a fabricated LED prototype. ► Thermal models setup and comparison between the classical and the new solutions. ► The impact of refrigerating liquid level on LED thermal and luminous performances. ► The relationship between different levels of liquid with LED prototype performances.

Sustainable LED Fluorescent Light Replacement Technology

Energy Technology Data Exchange (ETDEWEB)

None, None

2011-09-30

Ilumisys and the National Center for Manufacturing Sciences (NCMS) partnered on a three-year project awarded by the United States (U.S.) Department of Energy (DOE), to quantify the impacts of LED lamps, incandescent lamps and fluorescent benchmark lamps over a product lifecycle – i.e. to develop a sustainable design and manufacturing strategy that addresses product manufacturing, use, recycling and disposal scenarios for LED-based lighting. Based on the knowledge gained from extensive product tear-down studies of fluorescent and screw-in lighting products, lifecycle assessment tools, and accelerated lifecycle testing protocols, an interactive Sustainable LED Design Guide has been developed to aid architectural and lighting designers and engineers in making design decisions that consider three important environmental impacts (greenhouse gas emissions, energy use and mercury emission) across all phases of the life of an LED lighting product. Critical information developed for the lifecycle analysis and product feature comparisons is the useful life of the lighting product as well as its performance. The Design Guide is available at www.ncms.org, and was developed based on operational and durability testing of a variety of lighting products including power consumption, light output, and useful life of a lamp in order to allow a more realistic comparison of lamp designs. This report describes the main project tasks, results and innovative features of the lifecycle assessment (LCA)-based design tools, and the key considerations driving the sustainable design of LED lighting systems. The Design Guide incorporates the following three novel features for efficiently evaluating LED lighting features in value-chains: Bill-of-Materials (BOM) Builder – Designers may import process data for each component and supply functional data for the product, including power, consumption, lumen output and expected useful life: Environmental Impact Review – Designs are comparable

Goniometric characterization of LED based greenhouse lighting

DEFF Research Database (Denmark)

Thorseth, Anders; Lindén, Johannes; Corell, Dennis Dan

2015-01-01

This paper describes a demonstration of goniospectroradiometry for characterizations of new light emitting diode (LED) based luminaries for enhanced photosynthesis in greenhouses. It highlights the differences between measurement of the traditional high pressure sodium (HPS) luminaries and the LED...

Testing high brightness LEDs relative to application environment

Science.gov (United States)

Singer, Jeffrey; Mangum, Scott; Lundberg, John

2006-08-01

Application of light emitting diodes is expanding as the luminous output and efficiencies of these devices improve. At the same time, the number of LED package types is increasing, making it challenging to determine the appropriate device for use in lighting product designs. A range of factors should be considered when selecting a LED for an application including color coordinates, luminous efficacy, cost, lumen maintenance, application life, packaging and manufacturability. Additional complexities can be introduced as LED packages become obsolete and replacement parts must be selected. The replacement LED characteristics must be understood and assessed against the parameters of the original device, in order to determine if the change will be relatively simple or will force other end-product changes. While some characteristics are readily measured and compared, other factors, such as lumen maintenance, are difficult to verify. This paper will discuss the characteristics of a LED that should be considered during the design process as well as methods to validate these characteristics, particularly those which are not typically on data sheets or, are critical to the design and warrant additional validation. Particular attention will be given to LED lumen maintenance. While published manufacturer data typically provides temperature versus performance curves, the data may not be useful depending upon the application's operating environment. Models must be created to estimate the LED's junction temperature and degradation curve at the applied temperature in order to develop a more precise life estimate. This paper presents one approach to a LED device life and performance study designed with application environments in mind.

Determination of LEDs degradation with entropy generation rate

Science.gov (United States)

Cuadras, Angel; Yao, Jiaqiang; Quilez, Marcos

2017-10-01

We propose a method to assess the degradation and aging of light emitting diodes (LEDs) based on irreversible entropy generation rate. We degraded several LEDs and monitored their entropy generation rate ( S ˙ ) in accelerated tests. We compared the thermoelectrical results with the optical light emission evolution during degradation. We find a good relationship between aging and S ˙ (t), because S ˙ is both related to device parameters and optical performance. We propose a threshold of S ˙ (t) as a reliable damage indicator of LED end-of-life that can avoid the need to perform optical measurements to assess optical aging. The method lays beyond the typical statistical laws for lifetime prediction provided by manufacturers. We tested different LED colors and electrical stresses to validate the electrical LED model and we analyzed the degradation mechanisms of the devices.

A comparison of pediatric basic life support self-led and instructor-led training among nurses.

Science.gov (United States)

Vestergaard, Lone D; Løfgren, Bo; Jessen, Casper L; Petersen, Christina B; Wolff, Anne; Nielsen, Henrik V; Krarup, Niels H V

2017-02-01

Pediatric cardiac arrest carries a poor prognosis. Basic life support improves survival. Studies on pediatric basic life support (PBLS) training are sparse. The aim of our study was to investigate the effect of self-training in PBLS. We conducted a prospective controlled trial enrolling nurses from pediatric and maternity wards (n=29 in each group). Self-training, including a manikin and access to a web-based video on PBLS, was compared with a 2-h instructor-led course. Two weeks after training, all participants were tested in a mock scenario of pediatric cardiac arrest. Fifteen parameters equivalent to the steps in the PBLS algorithm - for example, effective ventilations, effective chest compressions, calling for help, and correct sequence of actions, were evaluated and rated dichotomously (1=approved or 0=not approved). No difference was observed in the baseline demographics between the self-training group and the instructor-led group. The participants in the self-training group accessed the website 2±1.5 times (mean±SD) and spent 41±25 min on the site. There was no significant difference between the two groups in the overall average score (10.5 in the self-training group vs. 10.0 in the instructor-led group, P=0.51) or in any of the 15 parameters. After the study, all participants felt that they had improved their skills and felt capable of performing PBLS. Self-training is not statistically different to instructor-led training in teaching PBLS. Self-evaluated confidence improved, but showed no difference between groups. PBLS may be disseminated through self-training.

Design of a cylindrical LED substrate without radiator

Science.gov (United States)

Tang, Fan; Guo, Zhenning

2017-12-01

To reduce the weight and production costs of light-emitting diode (LED) lamps, we applied the principle of the chimney effect to design a cylindrical LED substrate without a radiator. We built a 3D model by using Solidworks software and applied the flow simulation plug-in to conduct model simulation, thereby optimizing the heat source distribution and substrate thickness. The results indicate that the design achieved optimal cooling with a substrate with an upper extension length of 35 mm, a lower extension length of 8 mm, and a thickness of 1 mm. For a substrate of those dimensions, the highest LED chip temperature was 64.78 °C, the weight of the substrate was 35.09 g, and R jb = 7.00 K/W. If the substrate is powered at 8, 10, and 12 W, its temperature meets LED safety requirements. In physical tests, the highest temperature for a physical 8 W cylindrical LED substrate was 66 °C, which differed by only 1.22 °C from the simulation results, verifying the validity of the simulation. The designed cylindrical LED substrate can be used in high-power LED lamps that do not require radiators. This design is not only excellent for heat dissipation, but also for its low weight, low cost, and simplicity of manufacture.

Bioreactors in tissue engineering - principles, applications and commercial constraints.

Science.gov (United States)

Hansmann, Jan; Groeber, Florian; Kahlig, Alexander; Kleinhans, Claudia; Walles, Heike

2013-03-01

Bioreactor technology is vital for tissue engineering. Usually, bioreactors are used to provide a tissue-specific physiological in vitro environment during tissue maturation. In addition to this most obvious application, bioreactors have the potential to improve the efficiency of the overall tissue-engineering concept. To date, a variety of bioreactor systems for tissue-specific applications have been developed. Of these, some systems are already commercially available. With bioreactor technology, various functional tissues of different types were generated and cultured in vitro. Nevertheless, these efforts and achievements alone have not yet led to many clinically successful tissue-engineered implants. We review possible applications for bioreactor systems within a tissue-engineering process and present basic principles and requirements for bioreactor development. Moreover, the use of bioreactor systems for the expansion of clinically relevant cell types is addressed. In contrast to cell expansion, for the generation of functional three-dimensional tissue equivalents, additional physical cues must be provided. Therefore, bioreactors for musculoskeletal tissue engineering are discussed. Finally, bioreactor technology is reviewed in the context of commercial constraints. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Low Cost Lithography Tool for High Brightness LED Manufacturing

Energy Technology Data Exchange (ETDEWEB)

Andrew Hawryluk; Emily True

2012-06-30

The objective of this activity was to address the need for improved manufacturing tools for LEDs. Improvements include lower cost (both capital equipment cost reductions and cost-ofownership reductions), better automation and better yields. To meet the DOE objective of $1- 2/kilolumen, it will be necessary to develop these highly automated manufacturing tools. Lithography is used extensively in the fabrication of high-brightness LEDs, but the tools used to date are not scalable to high-volume manufacturing. This activity addressed the LED lithography process. During R&D and low volume manufacturing, most LED companies use contact-printers. However, several industries have shown that these printers are incompatible with high volume manufacturing and the LED industry needs to evolve to projection steppers. The need for projection lithography tools for LED manufacturing is identified in the Solid State Lighting Manufacturing Roadmap Draft, June 2009. The Roadmap states that Projection tools are needed by 2011. This work will modify a stepper, originally designed for semiconductor manufacturing, for use in LED manufacturing. This work addresses improvements to yield, material handling, automation and throughput for LED manufacturing while reducing the capital equipment cost.

Progress in extremely high brightness LED-based light sources

Science.gov (United States)

Hoelen, Christoph; Antonis, Piet; de Boer, Dick; Koole, Rolf; Kadijk, Simon; Li, Yun; Vanbroekhoven, Vincent; Van De Voorde, Patrick

2017-09-01

Although the maximum brightness of LEDs has been increasing continuously during the past decade, their luminance is still far from what is required for multiple applications that still rely on the high brightness of discharge lamps. In particular for high brightness applications with limited étendue, e.g. front projection, only very modest luminance values in the beam can be achieved with LEDs compared to systems based on discharge lamps or lasers. With dedicated architectures, phosphor-converted green LEDs for projection may achieve luminance values up to 200-300 Mnit. In this paper we report on the progress made in the development of light engines based on an elongated luminescent concentrator pumped by blue LEDs. This concept has recently been introduced to the market as ColorSpark High Lumen Density LED technology. These sources outperform the maximum brightness of LEDs by multiple factors. In LED front projection, green LEDs are the main limiting factor. With our green modules, we now have achieved peak luminance values of 2 Gnit, enabling LED-based projection systems with over 4000 ANSI lm. Extension of this concept to yellow and red light sources is presented. The light source efficiency has been increased considerably, reaching 45-60 lm/W for green under practical application conditions. The module architecture, beam shaping, and performance characteristics are reviewed, as well as system aspects. The performance increase, spectral range extensions, beam-shaping flexibility, and cost reductions realized with the new module architecture enable a breakthrough in LED-based projection systems and in a wide variety of other high brightness applications.

High Output LED-Based Profile Lighting Fixture

DEFF Research Database (Denmark)

Török, Lajos; Beczkowski, Szymon; Munk-Nielsen, Stig

2011-01-01

Recent developments in power light emitting diode (LED) industry have made LEDs suitable for being efficiently used in high intensity lighting fixtures instead of the commonly used high intensity discharge (HID) lamps. A high output LEDbased profile-light fixture is presented in this paper...

The possible ocular hazards of LED dental illumination applications.

Science.gov (United States)

Stamatacos, Catherine; Harrison, Janet L

2013-01-01

The use of high-intensity illumination via Light-Emitting Diode (LED) headlamps is gaining in popularity with dentists and student dentists. Practitioners are using LED headlamps together with magnifying loupes, overhead LED illumination and fiber-optic dental handpieces for long periods of time. Although most manufacturers of these LED illuminators advertise that their devices emit "white" light, these still consist of two spectral bands--the blue spectral band, with its peak at 445 nm, and the green with its peak at 555 nm. While manufacturers suggest that their devices emit "white" light, spectral components of LED lights from different companies are significantly different. Dental headlamp manufacturers strive to create a white LED, and they advertise that this type of light emitted from their product offers bright white-light illumination. However, the manufacturing of a white LED light is done through selection of a white LED-type based on the peak blue strength in combination with the green peak strength and thus creating a beam-forming optic, which determines the beam quality. Some LED illuminators have a strong blue-light component versus the green-light component. Blue-light is highly energized and is close in the color spectrum to ultraviolet-light. The hazards of retinal damage with the use of high-intensity blue-lights has been well-documented. There is limited research regarding the possible ocular hazards of usage of high-intensity illuminating LED devices. Furthermore, the authors have found little research, standards, or guidelines examining the possible safety issues regarding the unique dental practice setting consisting of the combined use of LED illumination systems. Another unexamined component is the effect of high-intensity light reflective glare and magnification back to the practitioner's eyes due to the use of water during dental procedures. Based on the result of Dr. Janet Harrison's observations of beginning dental students in a

White light-emitting diodes (LEDs) using (oxy)nitride phosphors

International Nuclear Information System (INIS)

Xie, R-J; Hirosaki, N; Sakuma, K; Kimura, N

2008-01-01

(Oxy)nitride phosphors have attracted great attention recently because they are promising luminescent materials for phosphor-converted white light-emitting diodes (LEDs). This paper reports the luminescent properties of (oxy)nitride phosphors in the system of M-Si-Al-O-N (M = Li, Ca or Sr), and optical properties of white LEDs using a GaN-based blue LED and (oxy)nitride phosphors. The phosphors show high conversion efficiency of blue light, suitable emission colours and small thermal quenching. The bichromatic white LEDs exhibit high luminous efficacy (∼55 lm W -1 ) and the multi-phosphor converted white LEDs show high colour rendering index (Ra 82-95). The results indicate that (oxy)nitride phosphors demonstrate their superior suitability to use as down-conversion luminescent materials in white LEDs

UV-LIGA: From Development to Commercialization

Directory of Open Access Journals (Sweden)

Grégoire Genolet

2014-07-01

Full Text Available A major breakthrough in UV-LIGA (Lithographie, Galvanoformung and Abformung started with the use of epoxy-based EPON® SU-8 photoresist in the mid-1990s. Using this photoresist has enabled the fabrication of tall and high aspect ratio structures without the use of a very expensive synchrotron source needed to expose the photoresist layer in X-ray LIGA. SU-8 photoresist appeared to be well-suited for LIGA templates, but also as a permanent material. Based on UV-LIGA and SU-8, Mimotec SA has developed processes to manufacture mold inserts and metallic components for various market fields. From one to three-level parts, from Ni to other materials, from simple to complicated parts with integrated functionalities, UV-LIGA has established itself as a manufacturing technology of importance for prototyping, as well as for mass-fabrication. This paper reviews some of the developments that led to commercial success in this field.

Commercial Optics for Space Surveillance and Astronomy

Science.gov (United States)

Ackermann, M.; Kopit, E.; McGraw, J.; Zimmer, P.

Since the first days of the space program, there have been both amateur and government satellite watchers. Large, expensive government systems with custom optics are still the most capable, but with modern sensors and high speed computers, amateur trackers are easily pushing the limits of what government systems achieved only a decade ago. A very recent trend in the space world is the emergence of commercial space operations centers. Once the exclusive purview of governments, corporations are now providing orbital environment awareness services to the operators of commercial satellites. The requirement for synoptic satellite observations has led to corporations developing world-wide observing networks. A problem facing both amateur and corporate observers is the limited availability of suitable optical systems. Most observing efforts rely on long focus (f/8 or greater) optical systems with focal reducers, and a somewhat limited field of view. Often, the cameras in use are not ideally matched to the optical system. While there are a few exceptions, the choices are not many. Celestron recently introduced the C-11 RASA optical system, with an 11-inch aperture and an f/2.2 focal ratio. This optical system is designed for dedicated imaging and is ideally suited for both wide-field astronomy and the detection and tracking of satellites. The larger C-14 RASA, to be introduced later this year, was specifically designed for wide-field imaging with large commercial CCDs. It offers greater sensitivity and a wider field of view than the smaller C-11 RASA and should prove to be the instrument of choice for both amateur and corporate satellite observers. We present data from satellite observations with a production model C-11 RASA and estimated performance for the new C-14 RASA.

Synthesis and luminescence properties of Ce{sup 3+}-doped Y{sub 3}Al{sub 3.5}Ga{sub 1.5}O{sub 12} green phosphor for white LEDs

Energy Technology Data Exchange (ETDEWEB)

Qiang, Yaochun [Fujian Key Laboratory of Advanced Materials, Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Yu, Yuxi, E-mail: yu_heart@xmu.edu.cn [Fujian Key Laboratory of Advanced Materials, Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Chen, Guolong [Fujian Engineering Research Center for Solid-state Lighting, Department of Electronic Science, Xiamen University, Xiamen 361005 (China); Fang, Jiyu [Advanced Materials Processing and Analysis Center, Department of Materials Science and Engineering, University of Central Florida, Orlando, FL 32816 (United States)

2016-04-15

A series of Ce{sup 3+}-doped Y{sub 3}Al{sub 3.5}Ga{sub 1.5}O{sub 12} green phosphors were successfully synthesized by a solid-state reaction method. The microstructure, morphology, luminescence spectra, luminescence quantum yield (QY) and thermal stability of the phosphor were investigated. The critical concentration of Ce{sup 3+} ions in Y{sub 3−m}Al{sub 3.5}Ga{sub 1.5}O{sub 12}:mCe{sup 3+} is m=0.06. The QY of Y{sub 2.94}Al{sub 3.5}Ga{sub 1.5}O{sub 12}:0.06Ce{sup 3+} phosphor is as high as 94% under excitation at 450 nm and its luminescence intensity at 150 °C still maintains 90% of that measured at 25 °C, which are just a little worse than those of commercial Lu{sub 3}Al{sub 5}O{sub 12}:Ce{sup 3+} green phosphor but much better than those of commercial (Sr,Ba){sub 2}SiO{sub 4}:Eu{sup 2+} green phosphor. A white LED lamp was fabricated by employing Y{sub 2.94}Al{sub 3.5}Ga{sub 1.5}O{sub 12}:0.06Ce{sup 3+} as a green phosphor and commercial (Ca,Sr)AlSiN{sub 3}:Eu{sup 2+} as a red phosphor (628 nm), its Ra value, correlated color temperature (CCT), CIE1931 chromaticity coordinates and luminous efficiency is 84, 3081 K, (x=0.4369, y=0.4142) and 102 lm/W, respectively. The experimental results demonstrate that Y{sub 2.94}Al{sub 3.5}Ga{sub 1.5}O{sub 12}:0.06Ce{sup 3+} is a promising green phosphor not only can be used for high color rendering index white LEDs but also for high-power white LEDs.

Flat-panel video resolution LED display system

Science.gov (United States)

Wareberg, P. G.; Kennedy, D. I.

The system consists of a 128 x 128 element X-Y addressable LED array fabricated from green-emitting gallium phosphide. The LED array is interfaced with a 128 x 128 matrix TV camera. Associated electronics provides for seven levels of grey scale above zero with a grey scale ratio of square root of 2. Picture elements are on 0.008 inch centers resulting in a resolution of 125 lines-per-inch and a display area of approximately 1 sq. in. The LED array concept lends itself to modular construction, permitting assembly of a flat panel screen of any desired size from 1 x 1 inch building blocks without loss of resolution. A wide range of prospective aerospace applications exist extending from helmet-mounted systems involving small dedicated arrays to multimode cockpit displays constructed as modular screens. High-resolution LED arrays are already used as CRT replacements in military film-marking reconnaissance applications.

Commercial Buildings Characteristics, 1992

Energy Technology Data Exchange (ETDEWEB)

1994-04-29

Commercial Buildings Characteristics 1992 presents statistics about the number, type, and size of commercial buildings in the United States as well as their energy-related characteristics. These data are collected in the Commercial Buildings Energy Consumption Survey (CBECS), a national survey of buildings in the commercial sector. The 1992 CBECS is the fifth in a series conducted since 1979 by the Energy Information Administration. Approximately 6,600 commercial buildings were surveyed, representing the characteristics and energy consumption of 4.8 million commercial buildings and 67.9 billion square feet of commercial floorspace nationwide. Overall, the amount of commercial floorspace in the United States increased an average of 2.4 percent annually between 1989 and 1992, while the number of commercial buildings increased an average of 2.0 percent annually.

A comparison of temperature and humidity effects on phosphor-converted LED packages and the prediction of remaining useful life with state estimation

Energy Technology Data Exchange (ETDEWEB)

Lall, Pradeep; Zhang, Hao; Davis, Lynn

2016-05-31

This paper focuses on the failure mechanisms and color stability of a commercially available high power LED under harsh environmental conditions. 3 groups of the same pc-HB warm white LED were used in the experiment. The first group was subjected to both high temperature and high relative humidity (85°C/85%RH) with a 350mA bias current. The second group was subjected to only temperature stress at 105°C with a 350mA bias current. The last group was subjected to extreme high temperature 175°C and high bias current (500mA). Samples were taken out from the chamber for both photometric and colorimetric analysis at periodic intervals to investigate the change of the optical parameters. The physics of failure due to the material degradation has been correlated with the change in the photometric and colorimetric parameters of the LED packages. At the end of the experiment, 6000 hours of data is projected forward with state estimation methods to compare with projections made with the TM-21 method. Experimental results shows that only optical parts degrades at high temperature conditions. However, at both high temperature and high relative humidity condition, the phosphor layer of the pc-LED can swell and the color stability of LEDs degrades significantly. Also, comparison between TM-21 method and state estimation method shows that state estimation can achieve the same goal with a relatively easy method.

Bridgeless SEPIC PFC Converter for Multistring LED Driver

Science.gov (United States)

Jha, Aman; Singh, Bhim

2018-05-01

This paper deals with Power Factor Correction (PFC) in Low Voltage High Current (LVHC) multi-string light emitting diode (LED) using a bridgeless (BL) single ended primary inductance converter (SEPIC). This application is designed for large area LED lighting with illumination control. A multi-mode LED dimming technique is used for the lighting control. The BL-SEPIC PFC converter is used as a load emulator for high power factor. The regulated low voltage from flyback converter is a source power to the synchronous buck converters for multi-string LED driver and forced cooling system for LED junction. The BL-SEPIC PFC converter inductor design is based on Discontinuous Inductor Current Modes (DICM) which provides good PFC at low cost. Test results are found quite satisfactory for universal input AC (90-265 V). There is significant improvement in the power factor and input current Total Harmonic Distortion (THD) with good margin of harmonic limits for lighting IEC 61000-3-2 Class C.

Status of the M-C Power IMHEX{reg_sign} MCFC commercialization program

Energy Technology Data Exchange (ETDEWEB)

Laurens, R.M.; Scroppo, J.A.; Petri, R.J.; Benjamin, T.G. [M-C Power Corp., Burr Ridge, IL (United States)

1996-12-31

Six years ago, M-C Power (MCP) developed a comprehensive business plan to commercialize molten carbonate fuel cell (MCFC) power plants. On an annual basis the plan has been reviewed and modified to adapt to identified end user needs and technological advancements. As a result, product definition kept abreast with marketing requirements. Over the last five years, there was order and reason for subtle shifts in supply, demand, competition and pricing policies. Today, however, traditional market assessment assumptions must be challenged. There is a revolution taking place. The revolution can be summed up in one word ... deregulation. Deregulation of the airline industry led to consideration of the natural gas industry. Now that natural gas deregulation is behind us, it is electric power and telecommunications that are receiving attention. Increased emphasis is being placed on achieving market-priced power. The net result will be thinner margins for the seller and the end user. What does this mean for the commercialization of molten carbonate fuel cells?

Carbon Monoxide (CO)

Science.gov (United States)

... automobile exhaust from attached garages tobacco smoke auto, truck, or bus exhaust from attached garages, nearby roads, ... Portable generators are useful when temporary or remote electric power is needed, but they also can be ...

Integrated parabolic nanolenses on MicroLED color pixels

Science.gov (United States)

Demory, Brandon; Chung, Kunook; Katcher, Adam; Sui, Jingyang; Deng, Hui; Ku, Pei-Cheng

2018-04-01

A parabolic nanolens array coupled to the emission of a nanopillar micro-light emitting diode (LED) color pixel is shown to reduce the far field divergence. For a blue wavelength LED, the total emission is 95% collimated within a 0.5 numerical aperture zone, a 3.5x improvement over the same LED without a lens structure. This corresponds to a half-width at half-maximum (HWHM) line width reduction of 2.85 times. Using a resist reflow and etchback procedure, the nanolens array dimensions and parabolic shape are formed. Experimental measurement of the far field emission shows a HWHM linewidth reduction by a factor of 2x, reducing the divergence over the original LED.

Setup of a LED light-pulser system for the OLYMPUS experiment; Aufbau eines LED-Lichtpulsersystems fuer das OLYMPUS-Experiment

Energy Technology Data Exchange (ETDEWEB)

Rehman, Waqaas

2011-12-15

The aim of this thesis consists in the construction and test of an external light-calibration system based on light-emitting diodes (LED) for the application at the symmetric Moller/Bhabha (SYMB) luminosity monitor. In chapter 2 the theoretical foundations of the OLYMPUS experiment, especially of the SYMB luminosity monitor are explained. Thereafter in chapter 3 the details of the setup of the OLYMPUS experiment and the fundamental properties of the SYMB detectors are discussed. In chapter 4 the whole concept of the LED light-pulser system is treated. In chapter 5 then test measurements with the ready LED light-pulser system are described. Thereby the light source shall be optimized in the shape that thereafter light pulses with short signal width are producable. Also different measurements for the unique characterization of the systems are performed. In chapter 6 light-intensity measurements during the operation of the LED light-pulser system are described.

Effect of commercial mineral-based additives on composting and compost quality.

Science.gov (United States)

Himanen, M; Hänninen, K

2009-08-01

The effectiveness of two commercial additives meant to improve the composting process was studied in a laboratory-scale experiment. Improver A (sulphates and oxides of iron, magnesium, manganese, and zinc mixed with clay) and B (mixture of calcium hydroxide, peroxide, and oxide) were added to source-separated biowaste:peat mixture (1:1, v/v) in proportions recommended by the producers. The composting process (T, emissions of CO(2), NH(3), and CH(4)) and the quality of the compost (pH, conductivity, C/N ratio, water-soluble NH(4)-N and NO(3)-N, water- and NaOH-soluble low-weight carboxylic acids, nutrients, heavy metals and phytotoxicity to Lepidium sarivum) were monitored during one year. Compared with the control, the addition of improver B increased pH by two units, led to an earlier elimination of water-soluble ammonia, an increase in nitrates, a 10-fold increase in concentrations of acetic acid, and shortened phytotoxicity period by half; as negative aspect it led to volatilization of ammonia. The addition of improver A led to a longer thermophilic stage by one week and lower concentrations of low-weight carboxylic acids (both water- and NaOH-extractable) with formic and acetic of similar amounts, however, most of the aspects claimed by the improver's producer were not confirmed in this trial.

78 FR 17875 - Commercial Driver's License Testing and Commercial Learner's Permit Standards

Science.gov (United States)

2013-03-25

... [Docket No. FMCSA-2007-27659] RIN 2126-AB59 Commercial Driver's License Testing and Commercial Learner's.... The 2011 final rule amended the commercial driver's license (CDL) knowledge and skills testing standards and established new minimum Federal standards for States to issue the commercial learner's permit...

UV-LEDs Efficiently Inactivate DNA and RNA Coliphages

Directory of Open Access Journals (Sweden)

Alyaa M. Zyara

2017-01-01

Full Text Available UV-LEDs are a new method of disinfecting drinking water. Some viruses are very resistant to UV and the efficiency of UV-LEDs to disinfect them needs to be studied. Drinking water was disinfected with UV-LEDs after spiking the water with MS2 and four UV- and/or Cl-resistant coliphages belonging to RNA or DNA coliphages isolated from municipal wastewater. UV-LEDs operating at a wavelength of 270 nm for 2 min with 120 mW of irradiation caused 0.93–2.73 Log10-reductions of coliphages tested in a reactor of a 5.2 L volume. Irradiation time of 10 min in the same system increased the Log10-reductions to 4.30–5.16. Traditional mercury UV (Hg-UV lamp at a 254 nm wavelength caused 0.67–4.08 Log10-reductions in 2 min and 4.56–7.21 Log10-reductions in 10 min in 10 mL of water. All coliphages tested except MS2 achieved 4 Log10-reductions with UV-LEDs at a dose that corresponded to 70 mWs/cm2 using Hg-UV. Thus, UV-LEDs are a promising method of disinfecting UV- and/or Cl-resistant viruses.

77 FR 26989 - Commercial Driver's License Testing and Commercial Learner's Permit Standards

Science.gov (United States)

2012-05-08

... [Docket No. FMCSA-2007-27659] RIN 2126-AB02 Commercial Driver's License Testing and Commercial Learner's... effective on July 8, 2011. That final rule amended the commercial driver's license (CDL) knowledge and skills testing standards and established new minimum Federal standards for States to issue the commercial...

A review of passive thermal management of LED module

NARCIS (Netherlands)

Ye, H.; Sau, K.; Zeijl, H. van; Gielen, A.W.J.; Zhang, G.

2011-01-01

Recently, the high-brightness LEDs have begun to be designed for illumination application. The increased electrical currents used to drive LEDs lead to thermal issues. Thermal management for LED module is a key design parameter as high operation temperature directly affects their maximum light

RISK MANAGEMENT AND EXPERTISE: UK: Strategies for Precautionary Commercialization of GM Crops

Directory of Open Access Journals (Sweden)

Levidow Les

2000-07-01

Full Text Available As genetically modified (GM products approach the market stage, the UK government and agro-food industry have faced a suspicious or hostile public. Since 1998 many retail chains have undertaken to exclude any GM-derived ingredients from their own-brand lines. This commercial blockage has intensified pressures for greater precaution, even for a moratorium on cultivating GM crops. Political protest has led to strategies for precautionary commercialization. Government and industry have cooperated to plan a “managed development” of GM crops. Across the agricultural supply chain, industry has devised voluntary guidelines to ensure segregation of GM crops and to limit the spread of GM herbicide-tolerance. In particular UK regulators seek to test the risk that broad-spectrum herbicide sprays could damage wildlife habitats; they have broadened the advisory expertise accordingly. These measures open up the precautionary content to further debate, at both national and EU levels. Market-stage precautions establish a means to test claims that GM crops are environmentally-friendly products. By translating public concerns into broader risk-assessment criteria, the UK procedure involves critics in potentially influencing standards of scientific evidence and environmental harm. This social process has become a prerequisite for legitimizing commercial use.

Architecture-Led Safety Process

Science.gov (United States)

2016-12-01

Contents Acknowledgments iv Abstract v 1 Introduction 1 2 Architecture -Led Processes and ALSA 2 3 ALSA Practices 5 3.1 Example System 8 4 Identify... Architecture Models 13 5 Identify Operational Hazards and Hazard Contributors 15 5.1 System Partitioning 15 5.2 Operational Context as a Control

Prototype Methodology for Designing and Developing Computer-Assisted Instruction

Science.gov (United States)

1986-08-01

contains essential information and is not set off with commas. For example: The lawn mower that is broken is in the garage. Use "which" whenever the...phrase that follows contains supplementary or incidental information. "Which" clauses are set of by a pair of commas. For example: The lawn mower , which...is broken, is in the garage. If the lawn mower that is broken is in the garage, whereas the lawn mower that is working is in the yard, then the

Enhanced Ce{sup 3+} photoluminescence by Li{sup +} co-doping in CaO phosphor and its use in blue-pumped white LEDs

Energy Technology Data Exchange (ETDEWEB)

Hao, Zhendong, E-mail: haozd@ciomp.ac.cn; Zhang, Xia; Luo, Yongshi; Zhang, Ligong; Zhao, Haifeng; Zhang, Jiahua, E-mail: zhangjh@ciomp.ac.cn

2013-08-15

In this paper, we demonstrate a method to improve the photoluminescence of CaO: Ce{sup 3+} phosphor and delineate its first use in blue-pumped white LEDs. The results show that the yellow emission of Ce{sup 3+} is enhanced by a factor of 1.88 by adding Li{sup +} into CaO host at 474 nm blue light excitation. On analyzing the diffuse reflection spectra and fluorescence decay curves, we reveal that the photoluminescence enhancement is originated from the rise of absorbance to the excitation photons but not from the improvement of the luminescent efficiency. Li{sup +}-improved CaO: Ce{sup 3+} exhibits more red component when it is compared with the commercial Y{sub 3}Al{sub 5}O{sub 12}: Ce{sup 3+} (YAG: Ce{sup 3+}) phosphor, indicating its potential application for high color rendering white LEDs. Thus, a white LED is fabricated by combining blue InGaN LED chip with CaO: Ce{sup 3+}, Li{sup +} phosphor and a warm white light with high color rendering index (R{sub a}) of 80, low correlated color temperature (T{sub c}) of 4524 K, and sufficient luminous efficiency of 50 lm W{sup −1} is obtained. -- Highlights: • The photoluminescence of Ce{sup 3+} in CaO host was enhanced by Li{sup +} co-doping. • A CaO: Ce{sup 3+}, Li{sup +} based white LED was fabricated for the first time. • An efficient warm white light was obtained. • CaO: Ce{sup 3+}, Li{sup +} is expected to be used as a yellow phosphor for blue-pumped white LEDs.

LED power consumption in joint illumination and communication system

NARCIS (Netherlands)

Deng, X.; Wu, Y.; Khalid, A.M.; Long, X.; Linnartz, J.-P.M.G.

This paper addresses the power penalty in an illumination LED caused by visible light communication (VLC). This study models the extra power consumption of the LED by taking into account the convex relation between the dissipated electrical power versus the LED current on one hand and the concave

Visual ergonomic evaluations on four different designs of LED traffic signs

Science.gov (United States)

Chen, Yi-Chun; Huang, Ting-Yuan; Lee, Tsung-Xian; Sun, Ching-Cherng

2017-08-01

To investigate the legibility and visual comfort of LED traffic signs, an ergonomic experiment is performed on four custom-designed LED traffic signs, including three self-luminous ones as LED lightbox, LED backlight and regional LED backlight, and one non-self-luminous sign with external LED lighting. The four signs are hanged side-by-side and evaluated by observers through questionnaires. The signage dimension is one-sixth of the real freeway traffic signs, and the observation distance is 25 m. The luminance of three self-luminous signs is 216 cd/m2. The illuminance of external LED lighting is 400 lux on the traffic sign. The ambient illuminance is 2.8 and 6.0 lux in two rounds. The results show that self-luminous traffic signs provide superior legibility, visual comfort and user preference than the non-self-luminous one. Among the three self-luminous signs, regional LED backlight is most susceptible to the ambient illumination. LED lightbox has significantly better preference score than LED backlight under darker ambient lighting. Only LED lightbox has significantly better visual comfort than external LED lighting in the brighter environment. Based on the four LED traffic signs evaluated in this study, we suggest LED lightbox as the prior choice. Further investigations on the effect of ambient illumination and other designs of self-luminous traffic signs are in progress.

The characterization of an economic and portable LED-based photoacoustic imaging system to facilitate molecular imaging

Directory of Open Access Journals (Sweden)

Ali Hariri

2018-03-01

Full Text Available Photoacoustic imaging (PAI is a non-invasive, high-resolution hybrid imaging modality that combines optical excitation and ultrasound detection. PAI can image endogenous chromophores (melanin, hemoglobin, etc. and exogenous contrast agents in different medical applications. However, most current equipment uses sophisticated and complicated OPO lasers with tuning and stability features inconsistent with broad clinical deployment. As the number of applications of PAI in medicine increases, there is an urgent need to make the imaging equipment more compact, portable, and affordable. Here, portable light emitting diode – based photoacoustic imaging (PLED-PAI was introduced and characterized in terms of system specifications, light source characterizations, photoacoustic spatial/temporal resolution, and penetration. The system uses two LED arrays attached to the sides of a conventional ultrasound transducer. The LED pulse repetition rate is tunable between 1 K Hz, 2 K Hz, 3 K Hz, and 4 K Hz. The axial resolution was 0.268 mm, and the lateral resolution was between 0.55 and 0.59 mm. The system could detect optical absorber (pencil lead at a depth of 3.2 cm and the detection limits of indocyanine green (ICG and methylene blue (MB were 9 μM and 0.78 mM. In vivo imaging of labeled human mesenchymal stem cells was achieved to confirm compatibility with small animal imaging. The characterization we report here may have value to other groups evaluating commercially available photoacoustic imaging equipment. Keywords: Portable photoacoustic imaging, LED, Optoacoustic imaging, Molecular imaging

High-Voltage LED Light Engine with Integrated Driver

Energy Technology Data Exchange (ETDEWEB)

Soer, Wouter [Lumileds LLC, San Jose, CA (United States)

2016-02-29

LED luminaires have seen dramatic changes in cost breakdown over the past few years. The LED component cost, which until recently was the dominant portion of luminaire cost, has fallen to a level of the same order as the other luminaire components, such as the driver, housing, optics etc. With the current state of the technology, further luminaire performance improvement and cost reduction is realized most effectively by optimization of the whole system, rather than a single component. This project focuses on improving the integration between LEDs and drivers. Lumileds has developed a light engine platform based on low-cost high-power LEDs and driver topologies optimized for integration with these LEDs on a single substrate. The integration of driver and LEDs enables an estimated luminaire cost reduction of about 25% for targeted applications, mostly due to significant reductions in driver and housing cost. The high-power LEDs are based on Lumileds’ patterned sapphire substrate flip-chip (PSS-FC) technology, affording reduced die fabrication and packaging cost compared to existing technology. Two general versions of PSS-FC die were developed in order to create the desired voltage and flux increments for driver integration: (i) small single-junction die (0.5 mm²), optimal for distributed lighting applications, and (ii) larger multi-junction die (2 mm² and 4 mm²) for high-power directional applications. Two driver topologies were developed: a tapped linear driver topology and a single-stage switch-mode topology, taking advantage of the flexible voltage configurations of the new PSS-FC die and the simplification opportunities enabled by integration of LEDs and driver on the same board. A prototype light engine was developed for an outdoor “core module” application based on the multi-junction PSS-FC die and the single-stage switch-mode driver. The light engine meets the project efficacy target of 128 lm/W at a luminous flux

EVALUATING THE CULTURE-LED REGENERATION

Directory of Open Access Journals (Sweden)

D'Angelo Francesca

2010-12-01

Full Text Available The aim of the paper is to propose a new approach to urban planning, evaluating the culture-led regeneration processes. In the last few years, the cultural turn in urban planning played a central role in the urban studies. In this way we try to elaborate a more robust perspective interpreting the complex phenomenology emerging from the culture-led regeneration processes. Within the concept of complexity we discuss about the metabolic process that are the processes necessary to transform energy, material and information in goods and service functional to the complex urban system life. The approach that will be employed is the MuSIASEM that is based on several novel concept and an innovative methods never applied in this research field.

The impact of social and organizational factors on workers' use of personal protective equipment: a multilevel approach.

Science.gov (United States)

Torp, Steffen; Grøgaard, Jens B; Moen, Bente E; Bråtveit, Magne

2005-08-01

On the basis of the job demands-control-support model by Karasek and Theorell, we investigated how social and organizational factors influence workers' use of personal protective equipment (PPE). A cross-sectional study was performed among 1420 workers in 203 motor vehicle-repair garages. Multilevel modeling was performed to account for the hierarchical structure of the data. Social and management support correlated positively with PPE use at the worker level. Low demands measured at the garage level and having a health and safety management system at the garage also correlated with active use of PPE. An interaction effect between social support and garage-level demands was observed. In addition to health information and provision of PPE, focusing on social and organizational factors seems necessary to get more workers to comply with the instructions on PPE use.

Competing in the Global LED Industry: The Case of Taiwan

Directory of Open Access Journals (Sweden)

Yu-Shan Su

2014-01-01

Full Text Available Light-emitting diode (LED is a very essential application for energy-savings nowadays. The revenue of the Taiwan LED components industry is ranked top one in the world, followed by that of Japan and South Korea. Based on the advantage of their electronics industry, Taiwanese LED companies create a unique model to compete with the international firms. Large international LED companies achieve economies of scale by vertically integrating their operations. Taiwanese LED companies specialize and achieve an optimal efficiency by vertically disintegrating across the upstream, midstream, and downstream sectors in the value chains. Taiwanese LED companies create economies of scale and economies of scope through a complete industrial value chain.

Intelligent styring af dynamisk LED belysning

DEFF Research Database (Denmark)

Thorseth, Anders; Corell, Dennis Dan; Hansen, Søren Stentoft

Denne slutrapport giver en kort beskrivelse af arbejdet, der er udført af DTU Fotonik i projektet ”Intelligent styring af dynamisk LED belysning” støttet af EUDP. Arbejdet er udført i perioden 2011‐2012 i samarbejde med Lighten.......Denne slutrapport giver en kort beskrivelse af arbejdet, der er udført af DTU Fotonik i projektet ”Intelligent styring af dynamisk LED belysning” støttet af EUDP. Arbejdet er udført i perioden 2011‐2012 i samarbejde med Lighten....

Scalable, Economical Fabrication Processes for Ultra-Compact Warm-White LEDs

Energy Technology Data Exchange (ETDEWEB)

Lowes, Ted [Cree, Inc., Durham, NC (United States)

2016-01-31

Conventional warm-white LED component fabrication consists of a large number of sequential steps which are required to incorporate electrical, mechanical, and optical functionality into the component. Each of these steps presents cost and yield challenges which multiply throughout the entire process. Although there has been significant progress in LED fabrication over the last decade, significant advances are needed to enable further reductions in cost per lumen while not sacrificing efficacy or color quality. Cree conducted a focused 18-month program to develop a new low-cost, high-efficiency light emitting diode (LED) architecture enabled by novel large-area parallel processing technologies, reduced number of fabrication steps, and minimized raw materials use. This new scheme is expected to enable ultra-compact LED components exhibiting simultaneously high efficacy and high color quality. By the end of the program, Cree fabricated warm-white LEDs with a room-temperature “instant on” efficacy of >135 lm/W at ~3500K and 90 CRI (when driven at the DOE baseline current density of 35 A/cm2). Cree modified the conventional LED fabrication process flow in a manner that is expected to translate into simultaneously high throughput and yield for ultra-compact packages. Building on its deep expertise in LED wafer fabrication, Cree developed these ultra-compact LEDs to have no compromises in color quality or efficacy compared to their conventional counterparts. Despite their very small size, the LEDs will also be robustly electrically integrated into luminaire systems with the same attach yield as conventional packages. The versatility of the prototype high-efficacy LED architecture will likely benefit solid-state lighting (SSL) luminaire platforms ranging from bulbs to troffers. We anticipate that the prototype LEDs will particularly benefit luminaires with large numbers of distributed compact packages, such as linear and area luminaires (e.g. troffers). The fraction of

Development of thermal LED Model | Kapitonov | Journal of ...

African Journals Online (AJOL)

Journal of Fundamental and Applied Sciences ... operating conditions of LEDs at the design stage, taking into account a cooling system in use. ... The created models will allow to reveal unfavorable thermal operating modes for LEDs and, ...

A novel wide range, real-time neutron fluence monitor based on commercial off the shelf gallium arsenide light emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Mukherjee, B., E-mail: bhaskar.mukherjee@uk-essen.de [Westdeutsches Protonentherapiezentrum Essen (WPE) gGmbH, Hufelandstrasse 55, D-45147 Essen (Germany); Hentschel, R. [Strahlenklinik, University Hospital Essen (Germany); Lambert, J. [Westdeutsches Protonentherapiezentrum Essen (WPE) gGmbH, Hufelandstrasse 55, D-45147 Essen (Germany); Deya, W. [Strahlenklinik, University Hospital Essen (Germany); Farr, J. [Westdeutsches Protonentherapiezentrum Essen (WPE) gGmbH, Hufelandstrasse 55, D-45147 Essen (Germany)

2011-10-01

Displacement damage produced by high-energy neutrons in gallium arsenide (GaAs) light emitting diodes (LED) results in the reduction of light output. Based on this principle we have developed a simple, cost effective, neutron detector using commercial off the shelf (COTS) GaAs-LED for the assessment of neutron fluence and KERMA at critical locations in the vicinity of the 230 MeV proton therapy cyclotron operated by Westdeutsches Protonentherapiezentrum Essen (WPE). The LED detector response (mV) was found to be linear within the neutron fluence range of 3.0x10{sup 8}-1.0x10{sup 11} neutron cm{sup -2}. The response of the LED detector was proportional to neutron induced displacement damage in LED; hence, by using the differential KERMA coefficient of neutrons in GaAs, we have rescaled the calibration curve for two mono-energetic sources, i.e. 1 MeV neutrons and 14 MeV neutrons generated by D+T fusion reaction. In this paper we present the principle of the real-time GaAs-LED based neutron fluence monitor as mentioned above. The device was calibrated using fast neutrons produced by bombarding a thick beryllium target with 14 MeV deuterons from a TCC CV 28 medical cyclotron of the Strahlenklinik University Hospital Essen.

Protection against methanol-induced retinal toxicity by LED photostimulation

Science.gov (United States)

Whelan, Harry T.; Wong-Riley, Margaret T. T.; Eells, Janis T.

2002-06-01

We have initiated experiments designed to test the hypothesis that 670-nm Light-Emitting Diode (LED) exposure will attenuate formate-induced retinal dysfunction in a rodent model of methanol toxicity. Methanol intoxication produces toxic injury to the retina. The toxic metabolite formed in methanol intoxication is formic acid, a mitochondrial toxin known to inhibit cytochrome oxidase activity. 670-nm LED light has been hypothesized to act by stimulating cytochrome oxidase activity. To test this hypothesis, one group of animals was intoxicated with methanol, a second group was intoxicated with methanol and LED-treated and a third group was untreated. LED treatment (670 nm for 1 min 45 seconds equals 50 mW/cm2, 4 joules/cm2) was administered at 5, 25, and 50 hours after the initial dose of methanol. At 72 hours of methanol intoxication, retinal function was assessed by measurement of ERG responses and retinas were prepared for histologic analysis. ERG responses recorded in methanol-intoxicated animals revealed profound attenuation of both rod-dominated and UV-cone mediated responses. In contrast, methanol- intoxicated animals exposed to LED treatment exhibited a nearly complete recovery of rod-dominated ERG responses and a slight improvement of UV-cone mediated ERG responses. LED treatment also protected the retina against the histopathologic changes produced by formate in methanol intoxication. These data provide evidence that LED phototherapy protects the retina against the cytotoxic actions of formate and are consistent with the hypothesis that LED photostimulation improves mitochondrial respiratory chain function.

Trends in prices to commercial energy consumers in the competitive Texas electricity market

International Nuclear Information System (INIS)

Zarnikau, Jay; Fox, Marilyn; Smolen, Paul

2007-01-01

To date, the price of electricity to commercial or business energy consumers has generally increased at greater rates in the areas of Texas where retail competition has been introduced than in areas that do not enjoy competition. Trends in commercial competitive prices have largely mirrored trends in residential prices. Market restructuring has tended to increase the sensitivity of retail electricity prices to changes in the price of natural gas, the marginal fuel used for generation in Texas. Consequently, the rapid increases in the commodity price of natural gas following restructuring led to increases in competitive electric rates which exceeded the increases in areas not exposed to restructuring, where the fuel component of electric rates tend to reflect a weighted average of the utilities' fuel costs. There is some evidence that pricing behavior by competitive retailers changed when the retailers affiliated with the incumbent utilities were permitted some pricing flexibility, resulting in a reduction in prices. (author)

Unidirectional visible light communication and illumination with LEDs

NARCIS (Netherlands)

Li, S.; Pandharipande, A.; Willems, F.M.J.

2016-01-01

Visible light communication (VLC) with light emitting diodes (LEDs) has attracted interest for interactive and networked lighting control, and consumer infotainment applications. In this paper, we propose an LED system for jointly achieving unidirectional VLC while providing flicker-free

Regression analysis for LED color detection of visual-MIMO system

Science.gov (United States)

Banik, Partha Pratim; Saha, Rappy; Kim, Ki-Doo

2018-04-01

Color detection from a light emitting diode (LED) array using a smartphone camera is very difficult in a visual multiple-input multiple-output (visual-MIMO) system. In this paper, we propose a method to determine the LED color using a smartphone camera by applying regression analysis. We employ a multivariate regression model to identify the LED color. After taking a picture of an LED array, we select the LED array region, and detect the LED using an image processing algorithm. We then apply the k-means clustering algorithm to determine the number of potential colors for feature extraction of each LED. Finally, we apply the multivariate regression model to predict the color of the transmitted LEDs. In this paper, we show our results for three types of environmental light condition: room environmental light, low environmental light (560 lux), and strong environmental light (2450 lux). We compare the results of our proposed algorithm from the analysis of training and test R-Square (%) values, percentage of closeness of transmitted and predicted colors, and we also mention about the number of distorted test data points from the analysis of distortion bar graph in CIE1931 color space.

Effective strategies to reduce commercial tobacco use in Indigenous communities globally: A systematic review.

Science.gov (United States)

Minichiello, Alexa; Lefkowitz, Ayla R F; Firestone, Michelle; Smylie, Janet K; Schwartz, Robert

2016-01-11

All over the world, Indigenous populations have remarkably high rates of commercial tobacco use compared to non-Indigenous groups. The high rates of commercial tobacco use in Indigenous populations have led to a variety of health issues and lower life expectancy than the general population. The objectives of this systematic review were to investigate changes in the initiation, consumption and quit rates of commercial tobacco use as well as changes in knowledge, prevalence, community interest, and smoke-free environments in Indigenous populations. We also aimed to understand which interventions had broad reach, what the common elements that supported positive change were and how Aboriginal self-determination was reflected in program implementation. We undertook a systematic review of peer-reviewed publications and grey literature selected from seven databases and 43 electronic sources. We included studies between 1994 and 2015 if they addressed an intervention (including provision of a health service or program, education or training programs) aimed to reduce the use of commercial tobacco use in Indigenous communities globally. Systematic cross-regional canvassing of informants in Canada and internationally with knowledge of Indigenous health and/or tobacco control provided further leads about commercial tobacco reduction interventions. We extracted data on program characteristics, study design and learnings including successes and challenges. In the process of this review, we investigated 73 commercial tobacco control interventions in Indigenous communities globally. These interventions incorporated a myriad of activities to reduce, cease or protect Indigenous peoples from the harms of commercial tobacco use. Interventions were successful in producing positive changes in initiation, consumption and quit rates. Interventions also facilitated increases in the number of smoke-free environments, greater understandings of the harms of commercial tobacco use and a

PV power system using hybrid converter for LED indictor applications

International Nuclear Information System (INIS)

Tseng, Sheng-Yu; Wang, Hung-Yuan; Chen, Chien-Chih

2013-01-01

Highlights: • This paper presents a LED indictor driving circuit with a PV arrays as its power source. • The perturb-and-observe method is adopted to extract the maximum power of PV arrays. • The proposed circuit structure has a less component counts and higher conversion efficiency. • A prototype of LED indictor driving circuit has been implemented to verify its feasibility. • The proposed hybrid converter is suitable for LED inductor applications. - Abstract: This paper presents a LED indictor driving circuit with a PV arrays as its power source. The LED indictor driving circuit includes battery charger and discharger (LED driving circuit). In this research, buck converter is used as a charger, and forward converter with active clamp circuit is adopted as a discharger to drive the LED indictor. Their circuit structures use switch integration technique to simplify them and to form the proposed hybrid converter, which has a less component counts, lighter weight, smaller size, and higher conversion efficiency. Moreover, the proposed hybrid converter uses a perturb-and-observe method to extract the maximum power from PV arrays. Finally, a prototype of an LED indictor driving circuit with output voltage of 10 V and output power of 20 W has been implemented to verify its feasibility. It is suitable for the LED inductor applications

76 FR 39018 - Commercial Driver's License Testing and Commercial Learner's Permit Standards; Corrections

Science.gov (United States)

2011-07-05

... [Docket No. FMCSA-2007-27659] RIN 2126-AB02 Commercial Driver's License Testing and Commercial Learner's..., 2011, that will be effective on July 8, 2011. This final rule amends the commercial driver's license... to issue the commercial learner's permit (CLP). Since the final rule was published, FMCSA identified...

A synthetic method of solar spectrum based on LED

Science.gov (United States)

Wang, Ji-qiang; Su, Shi; Zhang, Guo-yu; Zhang, Jian

2017-10-01

A synthetic method of solar spectrum which based on the spectral characteristics of the solar spectrum and LED, and the principle of arbitrary spectral synthesis was studied by using 14 kinds of LED with different central wavelengths.The LED and solar spectrum data were selected by Origin Software firstly, then calculated the total number of LED for each center band by the transformation relation between brightness and illumination and Least Squares Curve Fit in Matlab.Finally, the spectrum curve of AM1.5 standard solar spectrum was obtained. The results met the technical indexes of the solar spectrum matching with ±20% and the solar constant with >0.5.

Spectral Design Flexibility of LED Brings Better life

DEFF Research Database (Denmark)

Ou, Haiyan; Corell, Dennis Dan; Ou, Yiyu

2012-01-01

Light-emitting diodes (LEDs) are penetrating into the huge market of general lighting because they are energy saving and environmentally friendly. The big advantage of LED light sources, compared to traditional incandescent lamps and fluorescent light tubes, is the flexible spectral design to make...

University of Nevada Las Vegas LED Display Engineering

Energy Technology Data Exchange (ETDEWEB)

None

2010-08-31

The primary objective of this part of the project is to develop and implement a method that compensates for the inefficiency of the green LED. The proposed engineering solution which will be the backbone of this project will be to use RGBW combination in every pixel to save energy. Two different RGBW geometrical pixel configurations will be implemented and compared against traditional LED configurations. These configurations will be analyzed for energy efficiency while keeping the quality of the display the same. Cost of the addition of white LEDs to displays along with energy cost savings will be presented and analyzed.

Design of High Efficiency Illumination for LED Lighting

Directory of Open Access Journals (Sweden)

Yong-Nong Chang

2013-01-01

Full Text Available A high efficiency illumination for LED street lighting is proposed. For energy saving, this paper uses Class-E resonant inverter as main electric circuit to improve efficiency. In addition, single dimming control has the best efficiency, simplest control scheme and lowest circuit cost among other types of dimming techniques. Multiple serial-connected transformers used to drive the LED strings as they can provide galvanic isolation and have the advantage of good current distribution against device difference. Finally, a prototype circuit for driving 112 W LEDs in total was built and tested to verify the theoretical analysis.

Peer-led small groups: Are we on the right track?

Science.gov (United States)

Moore, Fraser

2017-10-01

Peer tutor-led small group sessions are a valuable learning strategy but students may lack confidence in the absence of a content expert. This study examined whether faculty reinforcement of peer tutor-led small group content was beneficial. Two peer tutor-led small group sessions were compared with one faculty-led small group session using questionnaires sent to student participants and interviews with the peer tutors. One peer tutor-led session was followed by a lecture with revision of the small group content; after the second, students submitted a group report which was corrected and returned to them with comments. Student participants and peer tutors identified increased discussion and opportunity for personal reflection as major benefits of the peer tutor-led small group sessions, but students did express uncertainty about gaps in their learning following these sessions. Both methods of subsequent faculty reinforcement were perceived as valuable by student participants and peer tutors. Knowing in advance that the group report would be corrected reduced discussion in some groups, potentially negating one of the major benefits of the peer tutor-led sessions. Faculty reinforcement of peer-tutor led small group content benefits students but close attention should be paid to the method of reinforcement.

Design Secondary Optical System Applied in White-LED General Illumination

International Nuclear Information System (INIS)

Chen Chen; Zhang Xianhui

2011-01-01

As a new generation of light source, LED has many advantages that other light sources do not have. However, due to the nonuniform lighting of LED, secondary LED optical system design is particularly important. Freeform surface tailoring method, an important method of lighting design, establishes a light intensity change model after smooth surface refraction (reflection) of the light and simplifies the solution process for more complex issues of solution using the free surface tailoring method. Based on this method, secondary LED optical system is designed, and the light intensity distribution is simulated after LED light passes through the secondary optical system. The results show that the method has not only simplified the calculation process of the free surface tailoring method, but also the designed LED secondary optical system has achieved the purpose of uniform lighting to a certain degree.

LED based opto-wetting platforms for micromixing

Science.gov (United States)

Thomas, Tony; Narayanan Unni, Harikrishnan

2018-02-01

The digital microfluidics utilizes the gradient in wettability for droplet transportation. This paper reports a novel technique of LED induced wetting ( Opto-wetting) where a single low power LED (Light emitting diode) emitting light of wavelength 395nm peak with luminous intensity of 300mcd (milli candela) is used to move two droplets of 20μL each on a photo responsive substrate of azobenzene (C12H10N2) coated PDMS (Poly Dimethyl Siloxane) substrate. The PDMS substrate of size 5cmx2cmx0.5cm were modified by thin film coating of Azobenzene dissolved in olive oil solution. The LED was aligned vertically on the top of the substrate. The pulsed operation of LED induces a spatial gradient of surface energy due to the reversible process of photo isomerization of Azobenzene molecules coated on the surface. The Photo-isomerization changes the conformation of the molecules thereby changing its surface energy .The change in surface energy of the substrate induces a change in contact angle of the droplet which initiates its movement. Two water droplets each of 20μL were dispensed on the substrate using micro syringe. Two droplets which were initially at a few cm distance apart were gradually moved towards the focus of light and merged together. The urine droplets (20μL) were moved and mixed with the red dye reagent (20μL) by controlling the light intensity of the LED. This concept provides a cost effective technique of droplet manipulation in the Lab on a chip domain where various multiplexed operations on proteins and DNA droplets can be done for point of care diagnostics.

A comparison of commercial light-emitting diode baited suction traps for surveillance of Culicoides in northern Europe.

Science.gov (United States)

Hope, Andrew; Gubbins, Simon; Sanders, Christopher; Denison, Eric; Barber, James; Stubbins, Francesca; Baylis, Matthew; Carpenter, Simon

2015-04-22

The response of Culicoides biting midges (Diptera: Ceratopogonidae) to artificial light sources has led to the use of light-suction traps in surveillance programmes. Recent integration of light emitting diodes (LED) in traps improves flexibility in trapping through reduced power requirements and also allows the wavelength of light used for trapping to be customized. This study investigates the responses of Culicoides to LED light-suction traps emitting different wavelengths of light to make recommendations for use in surveillance. The abundance and diversity of Culicoides collected using commercially available traps fitted with Light Emitting Diode (LED) platforms emitting ultraviolet (UV) (390 nm wavelength), blue (430 nm), green (570 nm), yellow (590 nm), red (660 nm) or white light (425 nm - 750 nm with peaks at 450 nm and 580 nm) were compared. A Centre for Disease Control (CDC) UV light-suction trap was also included within the experimental design which was fitted with a 4 watt UV tube (320-420 nm). Generalised linear models with negative binomial error structure and log-link function were used to compare trap abundance according to LED colour, meteorological conditions and seasonality. The experiment was conducted over 49 nights with 42,766 Culicoides caught in 329 collections. Culicoides obsoletus Meigen and Culicoides scoticus Downes and Kettle responded indiscriminately to all wavelengths of LED used with the exception of red which was significantly less attractive. In contrast, Culicoides dewulfi Goetghebuer and Culicoides pulicaris Linnaeus were found in significantly greater numbers in the green LED trap than in the UV LED trap. The LED traps collected significantly fewer Culicoides than the standard CDC UV light-suction trap. Catches of Culicoides were reduced in LED traps when compared to the standard CDC UV trap, however, their reduced power requirement and small size fulfils a requirement for trapping in logistically challenging areas or where many

Development of a commercial enzymes system for lignocellulosic biomass saccharification

Energy Technology Data Exchange (ETDEWEB)

Kumar, Manoj

2012-12-20

DSM Innovation Inc., in its four year effort was able to evaluate and develop its in-house DSM fungal cellulolytic enzymes system to reach enzyme efficiency mandates set by DoE Biomass program MYPP goals. DSM enzyme cocktail is uniquely active at high temperature and acidic pH, offering many benefits and product differentiation in 2G bioethanol production. Under this project, strain and process development, ratio optimization of enzymes, protein and genetic engineering has led to multitudes of improvement in productivity and efficiency making development of a commercial enzyme system for lignocellulosic biomass saccharification viable. DSM is continuing further improvement by additional biodiversity screening, protein engineering and overexpression of enzymes to continue to further lower the cost of enzymes for saccharification of biomass.

Thermo-mechanical model optimization of HB-LED packaging

NARCIS (Netherlands)

Yuan, C.A.; Erinc, M.; Gielen, A.W.J.; Waal, A. van der; Driel, W. van; Zhang, K.

2011-01-01

Lighting is an advancing phenomenon both on the technology and on the market level due to the rapid development of the solid state lighting technology. The efforts in improving the efficacy of high brightness LED's (HB-LED) have concentrated on the packaging architecture. Packaging plays a

The Lifetime Prediction of LED Drivers and Lamps

NARCIS (Netherlands)

Sun, B.

2017-01-01

Light-Emitting Diodes (LEDs) have become a very promising alternative lighting source with the main advantages of a longer lifetime and a higher efficiency than traditional ones. However, the LED lamp’s lifetime is compromised by its driver’s reliability. Although extensive studies have been made on

On-off switching patterns for smart LED lighting

NARCIS (Netherlands)

Linnartz, J.P.M.G.; Schenk, T.C.W.; Feri, L.; Yang, Hongming; Tjalkens, T.J.; Willems, F.M.J.

2009-01-01

This paper formulates a new communication problem for smart LED lighting sys tems designed for light effect control. It introduces the key requirements imposed on the design of the LED driving sequences, which include multiple access, arbi trary duty cycle and no disturbance caused on the normal

Flicker Reduction in LED-LCDs with Local Backlight

DEFF Research Database (Denmark)

Nadernejad, Ehsan; Mantel, Claire; Burini, Nino

2013-01-01

Local backlight dimming of LCD with LED backlight can reduce power consumption and improve quality of displayed images and videos. However, important variations of LED over time produce a visually annoying artifact called flickering. In this work, we propose a new algorithm to reduce flickering w...

Signal processing for LED lighting systems : illumination rendering and sensing

NARCIS (Netherlands)

Yang, H.

2010-01-01

Solid state lighting, employing high brightness light emitting diodes (LEDs), is becoming increasingly widely used. The advantages of LEDs include high radiative efficiency, long lifetime, limited heat generation and superior tolerance to humidity. Another important advantage of LED lighting systems

Virale commercials: de consument als marketeer. Onderzoek naar de redenen waarom consumenten virale commercials doorsturen: hun motieven, de inhoudskenmerken van viral commercials en de mediumcontext waarin virale commercials verschijnen

NARCIS (Netherlands)

Ketelaar, P.E.; Lucassen, P.; Kregting, G.H.J.

2010-01-01

Research into the reasons why consumers pass along viral commercials: their motives, the content characteristics of viral commercials and the medium context in which viral commercials appear. Based on the uses and gratifications perspective this study has determined which motives of consumers,

Color adjustable LED driver design based on PWM

Science.gov (United States)

Du, Yiying; Yu, Caideng; Que, Longcheng; Zhou, Yun; Lv, Jian

2012-10-01

Light-emitting diode (LED) is a liquid cold source light source that rapidly develops in recent years. The merits of high brightness efficiency, long duration, high credibility and no pollution make it satisfy our demands for consumption and natural life, and gradually replace the traditional lamp-house-incandescent light and fluorescent light. However, because of the high cost and unstable drive circuit, the application range is restricted. To popularize the applications of the LED, we focus on improving the LED driver circuit to change this phenomenon. Basing on the traditional LED drive circuit, we adopt pre-setup constant current model and introduce pulse width modulation (PWM) control method to realize adjustable 256 level-grays display. In this paper, basing on human visual characteristics and the traditional PWM control method, we propose a new PWM control timing clock to alter the duty cycle of PWM signal to realize the simple gamma correction. Consequently, the brightness can accord with our visual characteristics.

Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products Part 2: LED Manufacturing and Performance

Energy Technology Data Exchange (ETDEWEB)

Scholand, Michael; Dillon, Heather E.

2012-05-01

Part 2 of the project (this report) uses the conclusions from Part 1 as a point of departure to focus on two objectives: producing a more detailed and conservative assessment of the manufacturing process and providing a comparative LCA with other lighting products based on the improved manufacturing analysis and taking into consideration a wider range of environmental impacts. In this study, we first analyzed the manufacturing process for a white-light LED (based on a sapphire-substrate, blue-light, gallium-nitride LED pumping a yellow phosphor), to understand the impacts of the manufacturing process. We then conducted a comparative LCA, looking at the impacts associated with the Philips Master LEDbulb and comparing those to a CFL and an incandescent lamp. The comparison took into account the Philips Master LEDbulb as it is now in 2012 and then projected forward what it might be in 2017, accounting for some of the anticipated improvements in LED manufacturing, performance and driver electronics.

Commercial versus PARTNER study experience with the transfemoral Edwards SAPIEN valve for inoperable patients with severe aortic stenosis.

Science.gov (United States)

Pendyala, Lakshmana K; Minha, Sa'ar; Barbash, Israel M; Torguson, Rebecca; Magalhaes, Marco A; Okubagzi, Petros; Loh, Joshua P; Chen, Fang; Satler, Lowell F; Pichard, Augusto D; Waksman, Ron

2014-01-15

In patients with aortic stenosis who cannot have surgery, transcatheter aortic valve replacement using the Edwards SAPIEN valve has been shown to improve survival rate and is approved for commercial use in the United States. This study aims to assess the clinical profile, procedural characteristics, and in-hospital complications in patients treated with a commercial SAPIEN valve outside the clinical trial context. We retrospectively analyzed 69 consecutive patients who underwent transcatheter aortic valve replacement with a commercial SAPIEN valve compared with 55 Placement of AoRTic traNscathetER valves (PARTNER) trial patients from cohort B enrolled in the same institution by the same Heart Team. Compared with the commercial group, patients in the PARTNER cohort B had higher mean Society of Thoracic Surgeons score (10 ± 5 vs 9 ± 4, p = 0.04) and a lower rate of peripheral arterial disease (19% vs 44%, p = 0.004). Most patients in the commercial group had the procedure under conscious sedation (83% vs 66%, p = 0.03). Planned surgical cut down for vascular access was rare in the commercial group (1.4% vs 46%, p commercial group (7.2% vs 27%, p = 0.003; 2.9% vs 16%, p = 0.01; and 28% vs 60%, p commercial group. In conclusion, transfemoral commercial use of the Edwards SAPIEN valve for inoperable patients shows similar in-hospital mortality and stroke rates compared with PARTNER cohort B. The refinements in the procedure such as more conscious sedation, experience of the operators, and careful vascular planning in the commercial group led to lesser vascular and bleeding complications and shorter length of stay. Copyright © 2014 Elsevier Inc. All rights reserved.

Uniform LED illuminator for miniature displays

Science.gov (United States)

Medvedev, Vladimir; Pelka, David G.; Parkyn, William A.

1998-10-01

The Total Internally Reflecting (TIR) lens is a faceted structure composed of prismatic elements that collect a source's light over a much larger angular range than a conventional Fresnel lens. It has been successfully applied to the efficient collimation of light from incandescent and fluorescent lamps, and from light-emitting diodes (LEDs). A novel LED-powered collimating backlight is presented here, for uniformly illuminating 0.25'-diagonal miniature liquid- crystal displays, which are a burgeoning market for pagers, cellular phones, digital cameras, camcorders, and virtual- reality displays. The backlight lens consists of a central dual-asphere refracting section and an outer TIR section, properly curved with a curved exit face.

LED i Københavns Kommunes gadebelysning

DEFF Research Database (Denmark)

Bülow, Katja

2016-01-01

Artiklen i denne udgivelse formidler resultatet af en undersøgelse, hvor de visuelle forhold i Københavns Kommunes gader undersøges som resultat af gadens belysning. Der lægges vægt på metoden bag undersøgelsen og på hvordan indførelsen af LED forandrer belysningen i gaderne.......Artiklen i denne udgivelse formidler resultatet af en undersøgelse, hvor de visuelle forhold i Københavns Kommunes gader undersøges som resultat af gadens belysning. Der lægges vægt på metoden bag undersøgelsen og på hvordan indførelsen af LED forandrer belysningen i gaderne....

Analysis of technology and seminar on economic trends about High-intensity LED

International Nuclear Information System (INIS)

2003-09-01

This is divided into two parts. Contents of this report in the first part are technical trends on high-intensity LED which reports introduction of LED as compound semiconductor, white LED? patent issues, review on technology of High-intensity LED and Reliability of High-intensity LED. The second part deals with economic tends about High-intensity LED. This seminar was held to report analysis and economical trends about High-intensity LED by Korea Industrial Education Institute in 2003.

Uniformity of LED light illumination in application to direct imaging lithography

Science.gov (United States)

Huang, Ting-Ming; Chang, Shenq-Tsong; Tsay, Ho-Lin; Hsu, Ming-Ying; Chen, Fong-Zhi

2016-09-01

Direct imaging has widely applied in lithography for a long time because of its simplicity and easy-maintenance. Although this method has limitation of lithography resolution, it is still adopted in industries. Uniformity of UV irradiance for a designed area is an important requirement. While mercury lamps were used as the light source in the early stage, LEDs have drawn a lot of attention for consideration from several aspects. Although LED has better and better performance, arrays of LEDs are required to obtain desired irradiance because of limitation of brightness for a single LED. Several effects are considered that affect the uniformity of UV irradiance such as alignment of optics, temperature of each LED, performance of each LED due to production uniformity, and pointing of LED module. Effects of these factors are considered to study the uniformity of LED Light Illumination. Numerical analysis is performed by assuming a serious of control factors to have a better understanding of each factor.

A Novel Methodology for Measurements of an LED's Heat Dissipation Factor

Science.gov (United States)

Jou, R.-Y.; Haung, J.-H.

2015-12-01

Heat generation is an inevitable byproduct with high-power light-emitting diode (LED) lighting. The increase in junction temperature that accompanies the heat generation sharply degrades the optical output of the LED and has a significant negative influence on the reliability and durability of the LED. For these reasons, the heat dissipation factor, Kh, is an important factor in modeling and thermal design of LED installations. In this study, a methodology is proposed and experiments are conducted to determine LED heat dissipation factors. Experiments are conducted for two different brands of LED. The average heat dissipation factor of the Edixeon LED is 0.69, and is 0.60 for the OSRAM LED. By using the developed test method and comparing the results to the calculated luminous fluxes using theoretical equations, the interdependence of optical, electrical, and thermal powers can be predicted with a reasonable accuracy. The difference between the theoretical and experimental values is less than 9 %.

Vision communications based on LED array and imaging sensor

Science.gov (United States)

Yoo, Jong-Ho; Jung, Sung-Yoon

2012-11-01

In this paper, we propose a brand new communication concept, called as "vision communication" based on LED array and image sensor. This system consists of LED array as a transmitter and digital device which include image sensor such as CCD and CMOS as receiver. In order to transmit data, the proposed communication scheme simultaneously uses the digital image processing and optical wireless communication scheme. Therefore, the cognitive communication scheme is possible with the help of recognition techniques used in vision system. By increasing data rate, our scheme can use LED array consisting of several multi-spectral LEDs. Because arranged each LED can emit multi-spectral optical signal such as visible, infrared and ultraviolet light, the increase of data rate is possible similar to WDM and MIMO skills used in traditional optical and wireless communications. In addition, this multi-spectral capability also makes it possible to avoid the optical noises in communication environment. In our vision communication scheme, the data packet is composed of Sync. data and information data. Sync. data is used to detect the transmitter area and calibrate the distorted image snapshots obtained by image sensor. By making the optical rate of LED array be same with the frame rate (frames per second) of image sensor, we can decode the information data included in each image snapshot based on image processing and optical wireless communication techniques. Through experiment based on practical test bed system, we confirm the feasibility of the proposed vision communications based on LED array and image sensor.

Tuning the color point of a white LED

NARCIS (Netherlands)

Adhikary, Manashee; Meretska, Maryna; Ladovrechis, K.; Fokkema, Wouter K.; Vissenberg, Gilles; Lagendijk, Ad; Ijzerman, W.L.; Vos, Willem L.

2018-01-01

White light is conveniently characterized by a color point that is represented on the color space. Color point of white LED is fixed by the design parameters (e.g. Phosphor type and concentration). When the design parameters are chosen, the color point of the white LED cannot be changed. Here, we

Éalonnage de sources lumineuses de type LED

DEFF Research Database (Denmark)

Durix, Bastien; Quéau, Yvain; Lucas, Tom

We describe three calibration methods of a LED (light-emitting diode), in order to apply photometric stereo to a scene illuminated by LEDs. The most accurate of these methods will allow us to obtain very realistic 3D models. Nevertheless, the scene must remain still during the whole shooting sequ...

Dome diagnostics system of optical parameters and characteristics of LEDs

Science.gov (United States)

Peretyagin, Vladimir S.; Pavlenko, Nikita A.

2017-09-01

Scientific and technological progress of recent years in the production of the light emitting diodes (LEDs) has led to the expansion of areas of their application from the simplest systems to high precision lighting devices used in various fields of human activity. However, development and production (especially mass production) of LED lighting devices are impossible without a thorough analysis of its parameters and characteristics. There are many ways and devices for analysis the spatial, energy and colorimetric parameters of LEDs. The most methods are intended for definition only one parameter (for example, luminous flux) or one characteristic (for example, the angular distribution of energy or the spectral characteristics). Besides, devices used these methods are intended for measuring parameters in only one point or plane. This problem can be solved by using a dome diagnostics system of optical parameters and characteristics of LEDs, developed by specialists of the department OEDS chair of ITMO University in Russia. The paper presents the theoretical aspects of the analysis of LED's spatial (angular), energy and color parameters by using mentioned of diagnostics system. The article also presents the results of spatial), energy and color parameters measurements of some LEDs brands.

Reliability test and failure analysis of high power LED packages

International Nuclear Information System (INIS)

Chen Zhaohui; Zhang Qin; Wang Kai; Luo Xiaobing; Liu Sheng

2011-01-01

A new type application specific light emitting diode (LED) package (ASLP) with freeform polycarbonate lens for street lighting is developed, whose manufacturing processes are compatible with a typical LED packaging process. The reliability test methods and failure criterions from different vendors are reviewed and compared. It is found that test methods and failure criterions are quite different. The rapid reliability assessment standards are urgently needed for the LED industry. 85 0 C/85 RH with 700 mA is used to test our LED modules with three other vendors for 1000 h, showing no visible degradation in optical performance for our modules, with two other vendors showing significant degradation. Some failure analysis methods such as C-SAM, Nano X-ray CT and optical microscope are used for LED packages. Some failure mechanisms such as delaminations and cracks are detected in the LED packages after the accelerated reliability testing. The finite element simulation method is helpful for the failure analysis and design of the reliability of the LED packaging. One example is used to show one currently used module in industry is vulnerable and may not easily pass the harsh thermal cycle testing. (semiconductor devices)

Energy-Saving Tunnel Illumination System Based on LED's Intelligent Control

International Nuclear Information System (INIS)

Guo Shanshan; Wu Lan; Gu Hanting; Jiang Shuixiu

2011-01-01

At present there is a lot of electric energy wastage in tunnel illumination, whose design is based on the maximum brightness outside and the maximum vehicle speed all year round. LED's energy consumption is low, and the control of its brightness is simple and effective. It can be quickly adjusted between 0-100% of its maximum brightness, and will not affect the service life. Therefore, using LED as tunnel's illumination source, we can achieve a good energy saving effect. According to real-time data acquisition of vehicle speed, traffic flow and brightness outside the tunnel, the auto real-time control of tunnel illumination can be achieved. And the system regulated the LED luminance by means of combination of LED power module and intelligent control module. The tunnel information was detected by inspection equipments, which included luminometer, vehicle detector, and received by RTU(Remote Terminal Unit), then synchronously transmitted to PC. After data processing, RTU emitted the dimming signal to the LED driver to adjust the brightness of LED. Despite the relatively high cost of high-power LED lights, the enormous energy-saving effect and the well-behaved controllability is beyond compare to other lighting devices.

Judicial Reform and Commercial Justice : The Experience of Tanzania's Commercial Court

OpenAIRE

Finnegan, David Louis

2004-01-01

Policymakers in developing and transition economies recognize the important role played by judiciaries in creating an institutional environment conducive to robust private sector activity. In the case of Tanzania, the government, with the support of local business groups, international investors, and the donor community, created a specialized court dedicated to considering and resolving commercial and financial cases. The Commercial Division of the High Court of Tanzania (the "Commercial Cour...

Sponsored Schools and Commercialized Classrooms: Schoolhouse Commercializing Trends in the 1990's.

Science.gov (United States)

Molnar, Alex

This report analyzes commercializing trends in America's schools and classrooms, using data from database searches in seven categories of schoolhouse commercialism in the period 1990-97. The number of citations relating to commercializing activities can provide only a rough approximation of the scope and development of the phenomenon. The number…

Effects of LED or laser phototherapy on bone defects grafted with MTA and irradiated with laser or LED light: a comparative Raman spectroscopic study

Science.gov (United States)

Pinheiro, Antonio L. B.; Soares, Luiz G. P.; Barbosa, Artur Felipe S.; Silveira, Landulfo, Jr.

2012-03-01

We studied peaks of calcium hydroxyapatite - CHA on defects grafted with MTA, treated or not with Light Emitting Diode - LED or IR Laser. 54 rats were divided in 6 groups each subdivided into 3 subgroups (15,21,30d). LED (λ850 +/- 10nm) or IR Laser (λ850 nm) was applied over (LED) or in 4 points around the defect at 48 h intervals for 15 days. Raman readings were taken at the surface of the defect. The smaller overall intensity of the peak was found in Group MTA + Laser (1510.2 +/- 274.1) and the highest on Group LED (2322 +/- 715). There were no statistically significant differences between non-irradiated subjects on regards the CHA peaks. On the other hand, there were statistically significant differences between the Group Clot and LED, Clot and Laser, and Clot and MTA + Laser (p =0.01, p = 0.02, p = 0.003). There were no significant differences between Group MTA and MTA + LED (p=0.2) but significant differences were seen between Groups MTA and MTA + Laser (p=0.01). Significant differences were also observed between Groups LED and Laser (p <0.001) and between Groups MTA + LED and MTA + Laser (p=0.009). MTA, due to its characteristics, seemed to be directly affected by the light. However, the use of either phototherapy positively affected bone healing similarly as observed on different studies using other biomaterials. The overall analysis of our results indicated that the use of either light source resulted in a better, more advanced, and of quality bone repair.

Commercial Application of In-Space Assembly

Science.gov (United States)

Lymer, John; Hanson, Mark; Tadros, Al; Boccio, Joel; Hollenstein, Bruno; Emerick, Ken; Doughtery, Sean; Doggett, Bill; Dorsey, John T.; King, Bruce D.;

NASA commercial programs

Science.gov (United States)

1990-01-01

Highlights of NASA-sponsored and assisted commercial space activities of 1989 are presented. Industrial R and D in space, centers for the commercial development of space, and new cooperative agreements are addressed in the U.S. private sector in space section. In the building U.S. competitiveness through technology section, the following topics are presented: (1) technology utilization as a national priority; (2) an exploration of benefits; and (3) honoring Apollo-Era spinoffs. International and domestic R and D trends, and the space sector are discussed in the section on selected economic indicators. Other subjects included in this report are: (1) small business innovation; (2) budget highlights and trends; (3) commercial programs management; and (4) the commercial programs advisory committee.

Thermal Characterization and Lifetime Prediction of LED Boards for SSL Lamp

Directory of Open Access Journals (Sweden)

J. Formanek

2013-04-01

Full Text Available This work presents a detailed 3-D thermo-mechanical modelling of two LED board technologies to compare their performance. LED board are considered to be used in high power 800 lumen retrofit SSL (Solid State Lighting lamp. Thermal, mechanical and life time properties are evaluated by numerical modelling. Experimental results measured on fabricated LED board samples are compared to calculated data. Main role of LED board in SSL lamp is to transport heat from LED die to a heat sink and keep the thermal stresses in all layers as low as possible. The work focuses on improving of new LED board thermal management. Moreover, reliability and lifetime of LED board has been inspected by numerical calculation and validated by experiment. Thermally induced stress has been studied for wide temperature range that can affect the LED boards (-40 to +125°C. Numerical modelling of thermal performance, thermal stress distribution and lifetime has been carried out with ANSYS structural analysis where temperature dependent stress-strain material properties have been taken into account. The objective of this study is to improve not only the thermal performance of new LED board, but also identification of potential problems from mechanical fatigue point of view. Accelerated lifetime testing (e.g., mechanical is carried out in order to study the failure behaviour of current and newly developed LED board.

Aerial LED signage by use of crossed-mirror array

Science.gov (United States)

Yamamoto, Hirotsugu; Kujime, Ryousuke; Bando, Hiroki; Suyama, Shiro

2013-03-01

3D representation of digital signage improves its significance and rapid notification of important points. Real 3D display techniques such as volumetric 3D displays are effective for use of 3D for public signs because it provides not only binocular disparity but also motion parallax and other cues, which will give 3D impression even people with abnormal binocular vision. Our goal is to realize aerial 3D LED signs. We have specially designed and fabricated a reflective optical device to form an aerial image of LEDs with a wide field angle. The developed reflective optical device composed of crossed-mirror array (CMA). CMA contains dihedral corner reflectors at each aperture. After double reflection, light rays emitted from an LED will converge into the corresponding image point. The depth between LED lamps is represented in the same depth in the floating 3D image. Floating image of LEDs was formed in wide range of incident angle with a peak reflectance at 35 deg. The image size of focused beam (point spread function) agreed to the apparent aperture size.

Illuminating the Pecking Order in Off-Grid Lighting: A Demonstration of LED Lighting for Saving Energy in the Poultry Sector

Energy Technology Data Exchange (ETDEWEB)

Tracy, Jennifer; Mills, Evan

2010-11-06

The Lumina Project and Lighting Africa conducted a full-scale field test involving a switch from kerosene to solar-LED lighting for commercial broiler chicken production at an off-grid farm in Kenya. The test achieved lower operating costs, produced substantially more light, improved the working environment, and had no adverse effect on yields. A strategy using conventional solar-fluorescent lighting also achieved comparable yields, but entailed a six-fold higher capital cost and significantly higher recurring battery replacement costs. Thanks to higher energy and optical efficiencies, the LED system provided approximately twice the illumination to the chicken-production area and yet drew less than half the power.At the study farm, 3000 chickens were grown in each of three identical houses under kerosene, fluorescent, and LED lighting configurations. Under baseline conditions, a yearly expenditure of 1,200 USD is required to illuminate the three houses with kerosene. The LED system eliminates this fuel use and expense with a corresponding simple payback time of 1.5 years, while the solar-fluorescent system has a payback time of 9.3 years. The corresponding reduction in fuel expenditure in both cases represents a 15percent increase in after-tax net income (revenues minus expenses) across the entire business operation. The differential cost-effectiveness between the LED and fluorescent systems would be substantially greater if the fluorescent system were upsized to provide the same light as the LED system. Providing light with the fluorescent or LED systems is also far more economical than connecting to the grid in this case. The estimated grid-connection cost at this facility is 1.7 million Kenya Schillings (approximately 21,250 USD), which is nearly six-times the cost of the fluorescent system and 35-times the cost of the LED system.The LED system also confers various non-energy benefits. The relative uniformity of LED lighting, compared to the fluorescent or

Issues and solutions: opportunities for European LED manufacturers

Science.gov (United States)

Pearsall, T. P.

2007-09-01

Marketing studies by EPIC show significant revenue opportunities by 2012 for UHB-LEDs in the automotive, LCD backlighting, and architectural lighting sectors. The goal of this workshop on manufacturing issues is to consider five key issues for UHB-LED manufacturing and to propose solutions that will pave the way to full exploitation of the opportunities.

Solution of multi-element LED light sources development automation problem

Science.gov (United States)

Chertov, Aleksandr N.; Gorbunova, Elena V.; Korotaev, Valery V.; Peretyagin, Vladimir S.

2014-09-01

The intensive development of LED technologies resulted in the creation of multicomponent light sources in the form of controlled illumination devices based on usage of mentioned LED technologies. These light sources are used in different areas of production (for example, in the food industry for sorting products or in the textile industry for quality control, etc.). The use of LED lighting products in the devices used in specialized lighting, became possible due to wide range of colors of light, LED structures (which determines the direction of radiation, the spatial distribution and intensity of the radiation, electrical, heat, power and other characteristics), and of course, the possibility of obtaining any shade in a wide dynamic range of brightness values. LED-based lighting devices are notable for the diversity of parameters and characteristics, such as color radiation, location and number of emitters, etc. Although LED technologies have several advantages, however, they require more attention if you need to ensure a certain character of illumination distribution and/or distribution of the color picture at a predetermined distance (for example, at flat surface, work zone, area of analysis or observation). This paper presents software designed for the development of the multicomponent LED light sources. The possibility of obtaining the desired color and energy distribution at the zone of analysis by specifying the spatial parameters of the created multicomponent light source and using of real power, spectral and color parameters and characteristics of the LEDs is shown as well.

Warm white LEDs lighting over Ra=95 and its applications

Science.gov (United States)

Kobashi, Katsuya; Taguchi, Tsunemasa

2007-02-01

We have for the first time developed warm white LEDs lighting using a combination of near ultraviolet LED and three-band (red, green and blue) white phosphors. This LED has the average color-rendering index Ra=96. Moreover, special color-rendering index R9 (red) and R15 (face color of Japanese) are estimated to be 95 and 97, respectively. We will describe the results of evaluation on the medical lighting applications such as operation, treatment and endoscope experiments, application to the LED fashions and application to the Japanese antique art (ink painting) lighting.

Public Good or Commercial Opportunity: Case Studies in Remote Sensing Commercialization

Science.gov (United States)

Johnston, Shaida; Cordes, Joseph

2002-01-01

The U.S. Government is once again attempting to commercialize the Landsat program and is asking the private sector to develop a next generation mid-resolution remote sensing system that will provide continuity with the thirty-year data archive of Landsat data. Much of the case for commercializing the Landsat program rests on the apparently successful commercialization of high-resolution remote sensing activities coupled with the belief that conditions have changed since the failed attempt to commercialize Landsat in the 1980s. This paper analyzes the economic, political and technical conditions that prevailed in the 1980s as well as conditions that might account for the apparent success of the emerging high-resolution remote sensing industry today. Lessons are gleaned for the future of the Landsat program.

Smart LED allocation scheme for efficient multiuser visible light communication networks.

Science.gov (United States)

Sewaiwar, Atul; Tiwari, Samrat Vikramaditya; Chung, Yeon Ho

2015-05-18

In a multiuser bidirectional visible light communication (VLC), a large number of LEDs or an LED array needs to be allocated in an efficient manner to ensure sustainable data rate and link quality. Moreover, in order to support an increasing or decreasing number of users in the network, the LED allocation is required to be performed dynamically. In this paper, a novel smart LED allocation scheme for efficient multiuser VLC networks is presented. The proposed scheme allocates RGB LEDs to multiple users in a dynamic and efficient fashion, while satisfying illumination requirements in an indoor environment. The smart LED array comprised of RGB LEDs is divided into sectors according to the location of the users. The allocated sectors then provide optical power concentration toward the users for efficient and reliable data transmission. An algorithm for the dynamic allocation of the LEDs is also presented. To verify its effective resource allocation feature of the proposed scheme, simulations were performed. It is found that the proposed smart LED allocation scheme provides the effect of optical beamforming toward individual users, thereby increasing the collective power concentration of the optical signals on the desirable users and resulting in significantly increased data rate, while ensuring sufficient illumination in a multiuser VLC environment.

[Study on the safety of blue light leak of LED].

Science.gov (United States)

Shen, Chong-Yu; Xu, Zheng; Zhao, Su-Ling; Huang, Qing-Yu

2014-02-01

In this paper, the blue light properties of LED illumination devices have been investigated. Against the status quo of China's LED lighting, we measured the spectrum component of LED lamps and analyzed the photobiological safety under the current domestic and international standards GB/T 20145-2006/CIE S009/E: 2002 and IEC62471: 2006 standards as well as CTL-0744_2009-laser resolution, which provides the reference to the manufacture of LED lighting lamps as well as related safety standards and laws. If the radiance intensity of blue light in LED is lower than 100 W x m(-2) x Sr(-1), there is no harm to human eyes. LEDs will not cause harm to human eyes under normal use, but we should pay attention to the protection of special populations (children), and make sure that they avoid looking at a light source for a long time. The research has found that the blue-rich lamps can affect the human rule of work and rest, and therefore, the LED lamps with color temperature below 4 000 K and color rendering index of 80 are suitable for indoor use. At the same time, the lamps with different parameters should be selected according to the different distances.

Deep UV LEDs

Science.gov (United States)

Han, Jung; Amano, Hiroshi; Schowalter, Leo

2014-06-01

Deep ultraviolet (DUV) photons interact strongly with a broad range of chemical and biological molecules; compact DUV light sources could enable a wide range of applications in chemi/bio-sensing, sterilization, agriculture, and industrial curing. The much shorter wavelength also results in useful characteristics related to optical diffraction (for lithography) and scattering (non-line-of-sight communication). The family of III-N (AlGaInN) compound semiconductors offers a tunable energy gap from infrared to DUV. While InGaN-based blue light emitters have been the primary focus for the obvious application of solid state lighting, there is a growing interest in the development of efficient UV and DUV light-emitting devices. In the past few years we have witnessed an increasing investment from both government and industry sectors to further the state of DUV light-emitting devices. The contributions in Semiconductor Science and Technology 's special issue on DUV devices provide an up-to-date snapshot covering many relevant topics in this field. Given the expected importance of bulk AlN substrate in DUV technology, we are pleased to include a review article by Hartmann et al on the growth of AlN bulk crystal by physical vapour transport. The issue of polarization field within the deep ultraviolet LEDs is examined in the article by Braut et al. Several commercial companies provide useful updates in their development of DUV emitters, including Nichia (Fujioka et al ), Nitride Semiconductors (Muramoto et al ) and Sensor Electronic Technology (Shatalov et al ). We believe these articles will provide an excellent overview of the state of technology. The growth of AlGaN heterostructures by molecular beam epitaxy, in contrast to the common organo-metallic vapour phase epitaxy, is discussed by Ivanov et al. Since hexagonal boron nitride (BN) has received much attention as both a UV and a two-dimensional electronic material, we believe it serves readers well to include the

Wind energy. From the garage workshop to a global market. 25 years scientific accompaniment; Windenergie - von der Garagen-Werkstatt zum Weltmarkt. 25 Jahre wissenschaftliche Begleitung

Energy Technology Data Exchange (ETDEWEB)

Hahn, Berthold; Stuebig, Cornelia [Fraunhofer Institut fuer Windenergie und Energiesystemtechnik (IWES), Kassel (Germany); Ponick, Bernd [Fraunhofer Institut fuer Windenergie und Energiesystemtechnik (IWES), Kassel (Germany); Hannover Univ. (Germany); Keller, Sarina [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Koeln (Germany); Felder, Martin; Jachmann, Henning [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany)

2015-04-15

The plant technology for the use of wind energy on land is so sophisticated that the WEA can be operated as ''normal'' power plants to the grid. Of course, there are still potential for development, for example, in terms of improved reliability, or concerning the fledgling offshore use, always with an emphasis on the simultaneous reduction in costs. Although from the former garages workshops is little remaining, the production techniques are another major issue in terms of quality and costs. The cost of electricity from wind energy is taking account of external costs are already competitive with conventional power generation. To limit the costs of the energy transition one to expect from the wind energy as of the other technologies cost reduction. Various studies show that the wind energy supply in the balance is sufficient several times to provide the expected contribution to supply. [German] Die Anlagentechnologie fuer die Windenergienutzung an Land ist so ausgereift, dass die WEA als ''normale'' Kraftwerke am Netz betrieben werden koennen. Selbstverstaendlich bestehen weiterhin Entwicklungspotenziale, z. B. hinsichtlich verbesserter Zuverlaessigkeit oder bezueglich der noch jungen Offshore Nutzung, immer mit einem Augenmerk auf die gleichzeitige Kostenreduktion. Auch wenn von den ehemaligen Garagen Werkstaetten wenig uebrig geblieben ist, sind die Produktionstechniken ein weiteres wesentliches Thema bezueglich Qualitaet und Kosten. Die Kosteneffizienz der Stromerzeugung aus Windenergie ist unter Beruecksichtigung externer Kosten heute schon konkurrenzfaehig zur konventionellen Stromerzeugung. Zur Begrenzung der Kosten der Energiewende wird aber von der Windenergie wie von den anderen Technologien weiterhin eine Kostenreduktion erwartet. Diverse Studien zeigen, dass das Windenergieangebot in der Bilanz mehrfach ausreicht, um den erwarteten Beitrag zur Versorgung leisten zu koennen.

Understanding and controlling chromaticity shift in LED devices

Energy Technology Data Exchange (ETDEWEB)

Davis, Lynn; Mills, Karmann; Lamvik, Michael; Perkins, Curtis; Bobashev, Georgiy; Young, Joseph; Yaga, Robert; Johnson, Cortina

2017-05-30

Chromaticity shift in light-emitting diode (LED) devices arises from multiple mechanisms, and at least five different chromaticity shift modes (CSMs) have been identified to date. This paper focuses on the impacts of irreversible phosphor degradation as a cause of chromaticity shifts in LED devices. The nitride phosphors used to produce warm white LEDs are especially vulnerable to degradation due to thermal and chemical effects such as reactions with oxygen and water. As a result, LED devices utilizing these phosphors were found to undergo either a green shift or, less commonly, a red shift depending on the phosphor mix in the LED devices. These types of chromaticity shifts are classified as CSM-2 (green shift) and CSM-5 (red shift). This paper provides an overview of the kinetic processes responsible for green and red chromaticity shifts along with examples from accelerated stress testing of 6” downlights. Both CSMs appear to proceed through analogous mechanisms that are initiated at the surface of the phosphor. A green shift is produced by the surface oxidation of the nitride phosphor that changes the emission profile to lower wavelengths. As the surface oxidation reaction proceeds, reactant limitations slow the rate and bulk oxidation processes become more prevalent. We found that a red chromaticity shift arises from quenching of the green phosphor, also possibly due to surface reactions of oxygen, which shift the emission chromaticity in the red direction. In conclusion, we discuss the implications of these findings on projecting chromaticity.

Commercial Radio as Communication.

Science.gov (United States)

Rothenbuhler, Eric W.

1996-01-01

Compares the day-to-day work routines of commercial radio with the principles of a theoretical communication model. Illuminates peculiarities of the conduct of communication by commercial radio. Discusses the application of theoretical models to the evaluation of practicing institutions. Offers assessments of commercial radio deriving from…

LED lighting and the Next Generation of Greenhouse for Tomatoes. Proof of Principle; LED belichting en Het Nieuwe Telen bij tomaat. Proof of Principle

Energy Technology Data Exchange (ETDEWEB)

Dueck, T.; Janse, J.; Eveleens, B. [Wageningen UR Glastuinbouw, Wageningen (Netherlands); Nieboer, S.; Valstar, W.; Grootscholten, M. [GreenQ Improvement Centre, Bleiswijk (Netherlands)

2012-08-15

In this Proof of Principle project a tomato crop was grown under artificial lighting with the aim of 30% energy saving at the same level of production. Tomatoes (cultivar Komeett) were illuminated with 110 {mu}mol m{sup -2} s{sup -1} HPS (High Pressure Sodium) above the crop and 85 {mu}mol m{sup -2} s{sup -1} LED interlighting. The LEDs hung in 2 rows, approximately 40 cm above the lower leaves and the second strand at 40 or 70 cm above that. There were two types of LEDs used: production LEDs (light efficiency 1.6 {mu}mol m{sup -2} s{sup -1}, 87% red/13% blue) and inter-lighting LEDs (light efficiency 1.9 {mu}mol m{sup -2} s{sup -1}, 95% red/5% blue), with the same light intensity. At the start, the crop was given as much light as it could handle, and because the crop developed so well, the stem density was increased relatively early. This resulted in high fruit load, while insufficient light was available to compensate for the low levels of sunlight in the winter. In the 192 cm row spacing system the plants were too close to each other. Additional problems occurred with trace elements, lesser bumble bee activity, and a moist greenhouse climate which weakened the crop in the winter. Thus Botrytis occurred on the leaves and stems. The crop struggled with its recovery until early spring with more sunlight. Compared to a reference crop with 79 kg m{sup -2} tomatoes, 75 kg m{sup -2} were produced under-production LEDs, and 80 kg m{sup -2} under the interlighting LEDs, mainly because latter LEDs were used longer during the summer. 30% of the energy for dehumidification and heat energy, and 27% of the electricity was saved, relative to the reference crop. Thus it appears possible to save 30% energy with a near identical production [Dutch] In dit Proof of Principle project is een belichte tomatenteelt geteeld met als doel 30% energiebesparing bij een gelijke productie. Tomaten van het ras Komeett werden belicht met 110 {mu}mol m{sup -2} s{sup -1} SON-T belichting boven

LED Street Lighting Solutions: Flagstaff, Arizona as a Case Study

Science.gov (United States)

Hall, Jeffrey C.

2018-01-01

Dark-sky protection in Flagstaff, Arizona extends back to 1958, with the first ordinance in the City banning advertising floodlights. The current ordinance, adopted in 1989, is comprehensive and has played a critical role in maintaining the quality of the night sky for astronomy, tourism, public enjoyment, and other purposes. Flagstaff, like many communities around the world, is now working on a transition from legacy bulb-based technology to LED for its outdoor lighting. The City, Lowell Observatory, the U. S. Naval Observatory, and the Flagstaff Dark Skies Coalition have been working intensively for two years to identify an LED-based street lighting solution that will preserve the City's dark skies while meeting municipal needs. We will soon be installing test fixtures for an innovative solution incorporating narrow-band amber LED and modest amounts of low-CCT white LED. In this talk, I will review the types of LEDs available for outdoor lighting and discuss the plans for Flagstaff's street lighting in the LED era, which we hope will be a model for communities worldwide.

Iluminación LED. Un arma de doble filo

OpenAIRE

Sánchez de Miguel, Alejandro

2004-01-01

La iluminación LED es el futuro de la iluminación. Sin embargo, como toda tecnología, puede usarse de manera correcta o incorrecta. En el caso de los LED, el abaratamiento de la producción de luz podría provocar un aumento descontrolado de la Contaminación lumínica. Por otro, el uso correcto de los LED podría ser la solución al mismo mal por su capacidad de encendido casi instantáneo.

Progress and prospects of GaN-based LEDs using nanostructures

Science.gov (United States)

Zhao, Li-Xia; Yu, Zhi-Guo; Sun, Bo; Zhu, Shi-Chao; An, Ping-Bo; Yang, Chao; Liu, Lei; Wang, Jun-Xi; Li, Jin-Min

2015-06-01

Progress with GaN-based light emitting diodes (LEDs) that incorporate nanostructures is reviewed, especially the recent achievements in our research group. Nano-patterned sapphire substrates have been used to grow an AlN template layer for deep-ultraviolet (DUV) LEDs. One efficient surface nano-texturing technology, hemisphere-cones-hybrid nanostructures, was employed to enhance the extraction efficiency of InGaN flip-chip LEDs. Hexagonal nanopyramid GaN-based LEDs have been fabricated and show electrically driven color modification and phosphor-free white light emission because of the linearly increased quantum well width and indium incorporation from the shell to the core. Based on the nanostructures, we have also fabricated surface plasmon-enhanced nanoporous GaN-based green LEDs using AAO membrane as a mask. Benefitting from the strong lateral SP coupling as well as good electrical protection by a passivation layer, the EL intensity of an SP-enhanced nanoporous LED was significantly enhanced by 380%. Furthermore, nanostructures have been used for the growth of GaN LEDs on amorphous substrates, the fabrication of stretchable LEDs, and for increasing the 3-dB modulation bandwidth for visible light communication. Project supported by the National Natural Science Foundation of China (Grant No. 61334009), the National High Technology Research and Development Program of China (Grant Nos. 2015AA03A101 and 2014BAK02B08), China International Science and Technology Cooperation Program (Grant No. 2014DFG62280), the “Import Outstanding Technical Talent Plan” and “Youth Innovation Promotion Association Program” of the Chinese Academy of Sciences.

High-power UV-LED degradation: Continuous and cycled working condition influence

Science.gov (United States)

Arques-Orobon, F. J.; Nuñez, N.; Vazquez, M.; Segura-Antunez, C.; González-Posadas, V.

2015-09-01

High-power (HP) UV-LEDs can replace UV lamps for real-time fluoro-sensing applications by allowing portable and autonomous systems. However, HP UV-LEDs are not a mature technology, and there are still open issues regarding their performance evolution over time. This paper presents a reliability study of 3 W UV-LEDs, with special focus on LED degradation for two working conditions: continuous and cycled (30 s ON and 30 s OFF). Accelerated life tests are developed to evaluate the influence of temperature and electrical working conditions in high-power LEDs degradation, being the predominant failure mechanism the degradation of the package. An analysis that includes dynamic thermal and optical HP UV-LED measurements has been performed. Static thermal and stress simulation analysis with the finite element method (FEM) identifies the causes of package degradation. Accelerated life test results prove that HP UV-LEDs working in cycled condition have a better performance than those working in continuous condition.

Response of Eustoma Leaf Phenotype and Photosynthetic Performance to LED Light Quality

Directory of Open Access Journals (Sweden)

Md Zohurul Kadir Roni

2017-10-01

Full Text Available In a controlled environment, light from light-emitting diodes (LEDs has been associated with affecting the leaf characteristics of Eustoma. LEDs help plant growth and development, yet little is known about photosynthetic performance and related anatomical features in the early growth stage of Eustoma leaves. In this study, we examined the effects of blue (B, red (R, and white (W LEDs on the photosynthetic performance of Eustoma leaves, as well as leaf morphology and anatomy including epidermal layer thickness, palisade cells, and stomatal characteristics. Leaves grown under B LEDs were thicker and had a higher chlorophyll content than those grown under the R and W LEDs. Leaves under B LEDs had greater net photosynthetic rates (A, stomatal conductance (gs, and transpiration rates (E, especially at a higher photon flux density (PPFD, that resulted in a decrease in the intercellular CO2 concentration (Ci, than leaves under the W and R LEDs. B LEDs resulted in greater abaxial epidermal layer thickness and palisade cell length and width than the R and W LED treatments. The palisade cells also developed a more cylindrical shape in response to the B LEDs. B LED leaves also showed greater guard cell length, breadth, and area, and stomatal density, than W or R LEDs, which may contribute to increased A, gs and E at higher PPFDs.

Introduction of commercialization success cases with JAEA's result development business

International Nuclear Information System (INIS)

Takenaka, Shingo; Yoshii, Fumio; Nakajima, Junsaku

2009-01-01

JAEA's result development business has conducted joint researches on 69 subjects for ten years and brought about 26 commercialization success cases. This article presented six cases to contribute the activation of local industry to some extend. Demineralization technology for circulating water of air-conditioning and heating was developed using graft polymers. Biological effects of irradiated chitosan led to product of plant energizer oligo-glucosamine-L'. High performance gas analyzer developed for fusion research was used for componential analysis of yeast starter of old sake for taste check. Titanium-clad materials for knife were produced with hot rolling machine. Application of biodegradable polymer (polylactic acid) to demonstration lenses was developed. Surface condition and salt concentration sensors for snowy and icy roads were developed based on JAEA's patents. (T. Tanaka)

About the Little Red Riding Hood, Durex and anger: production, meaning and reception of one fairy tale and one commercial ad

Directory of Open Access Journals (Sweden)

Dragana Antonijević

2016-03-01

Full Text Available By applying the semiological analysis, this paper considers planned and unplanned readings of a provocative domestic commercial, which, in order to convey its message, transposed the Little Red Riding Hood’s character in accordance with the advertised product – Durex condoms. This commercial caused furious reactions of parents who took legal action for breaching the Law on public advertising and, especially, "harming children’s sensibility and integrity". Provocative billboards also caused numerous comments in the daily newspapers, in the Internet chat rooms, with some considering the commercial vulgar and offensive and others having no problem with it, adding that the ones who took offence belonged to those puritan and conservative layers of the society. In order to discover the reasons to this kind of reactions, I started with researching how the commercial was made and what kind of message it offered. Next, I reconsidered the meaning of the very fairy tale "The Red Riding Hood". Its original version, which contains open sexual allusions, is quite different to the changed versions offered by Charles Perrault and the Grimm brothers. Their versions can be seen as fakelore, since they outrageously intervened on the plot and the meaning of the original fairy tale. However, since the Grimm brothers’ version is the most popular, it is a fact that our public reacted with such anger led by the meaning of their version, which accentuates overeating and cannibalism, and not sexual development of girls, which is the basic message of the original version. This is where the "communicational noise" that led to those negative reactions came from. By discovering the true meaning of the tale, the answer is given to the question whether the advertising agency made a slip up, or it had actually found the right way to communicate the hidden message of the tale, and at the same time ruin the advertising campaign for which it was used. In the end, range and

White LED motorcycle headlamp design

Science.gov (United States)

Sun, Wen-Shing

2015-09-01

The motorcycle headlamp is composed of a white LED module, an elliptical reflector, a parabolic reflector and a toric lens. We use non-sequential ray to improve the optical efficiency of the compound reflectors. Using the toric lens can meet ECE_113 regulation and obtain a good uniformity.

Commercialization of DOE isotope production

International Nuclear Information System (INIS)

Laflin, S.

1997-01-01

This paper describes the business structure and operations of MAC Isotopes (MACI) L.L.C., a newly created business resulting from the commercialization of a former U.S. Department of Energy (DOE) mission at the Idaho National Engineering and Environmental Laboratory (INEEL). MACI began its commercial operations on October 1, 1996, and is the first U.S. commercial isotope production business to result from the commercialization of DOE facilities or programs. The commercialization was the culmination of an -2-yr competitive procurement process by the DOE and Lockheed Martin Idaho Technologies Company (LMITCO). MACI was selected from this competitive process as the commercial business of choice on the basis of providing the best value to the DOE/LMITCO and having the greatest potential for commercial success

Multifaceted Pharmacist-led Interventions in the Hospital Setting

DEFF Research Database (Denmark)

Skjøt-Arkil, Helene; Olesen, Carina Lundby; Kjeldsen, Lene Juel

2018-01-01

Clinical pharmacy services often comprise complex interventions. In this MiniReview, we conducted a systematic review aiming to evaluate the impact of multifaceted pharmacist-led interventions in a hospital setting. We searched MEDLINE, Embase, Cochrane Library and CINAHL for peer-reviewed articles...... published from 2006 to 1 March 2018. Controlled trials concerning hospitalized patients in any setting receiving patient-related multifaceted pharmacist-led interventions were considered. All types of outcomes were accepted. Inclusion and data extraction was performed. Study characteristics were collected......) showed no significant results. This rMiniReview indicates that multifaceted pharmacist-led interventions in a hospital setting may improve the quality of medication use, reduce hospital visits and length of stay, while no effect was seen on mortality, patient-reported outcomes and cost...

Colorimetry and efficiency of white LEDs: Spectral width dependence

Energy Technology Data Exchange (ETDEWEB)

Taylor, Elaine; Edwards, Paul R.; Martin, Robert W. [Department of Physics, SUPA, Strathclyde University, Glasgow (United Kingdom)

2012-03-15

The potential colour rendering capability and efficiency of white LEDs constructed by a combination of individual red, green and blue (RGB) LEDs are analysed. The conventional measurement of colour rendering quality, the colour rendering index (CRI), is used as well as a recently proposed colour quality scale (CQS), designed to overcome some of the limitations of CRI when narrow-band emitters are being studied. The colour rendering performance is maximised by variation of the peak emission wavelength and relative intensity of the component LEDs, with the constraint that the spectral widths follow those measured in actual devices. The highest CRI achieved is 89.5, corresponding to a CQS value of 79, colour temperature of 3800 K and a luminous efficacy of radiation (LER) of 365 lm/W. By allowing the spectral width of the green LED to vary the CRI can be raised to 90.9, giving values of 82.5 and 370 lm/W for the CQS and LER, respectively. The significance of these values are discussed in terms of optimising the possible performance of RGB LEDs. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Commercial Banking Industry Survey.

Science.gov (United States)

Bright Horizons Children's Centers, Cambridge, MA.

Work and family programs are becoming increasingly important in the commercial banking industry. The objective of this survey was to collect information and prepare a commercial banking industry profile on work and family programs. Fifty-nine top American commercial banks from the Fortune 500 list were invited to participate. Twenty-two…

76 FR 126 - Requirement for Commercial Users To Use Commercial Public Key Information (PKI) Certificate

Science.gov (United States)

2011-01-03

... DEPARTMENT OF DEFENSE Department of the Army Requirement for Commercial Users To Use Commercial..., SDDC will require all commercial accounts accessing transportation systems and applications to use a commercial PKI certificate or Transportation Workers Identification Credential (TWIC). This requirement will...

High-energy radiation and polymers: A review of commercial processes and emerging applications

International Nuclear Information System (INIS)

Clough, R.L.

2001-01-01

Ionizing radiation has been found to be widely applicable in modifying the structure and properties of polymers, and can be used to tailor the performance of either bulk materials or surfaces. Fifty years of research in polymer radiation chemistry has led to numerous applications of commercial and economic importance, and work remains active in the application of radiation to practical uses involving polymeric materials. This paper provides a survey of radiation-processing methods of industrial interest, ranging from technologies already commercially well established, through innovations in the active R and D stage which show exceptional promise for future commercial use. Radiation-processing technologies are discussed under the following categories: cross-linking of plastics and rubbers, curing of coatings and inks, heat-shrink products, fiber-matrix composites, chain-scission for processing control, surface modification, grafting, hydrogels, sterilization, natural product enhancement, plastics recycling, ceramic precursors, electronic property materials, ion-track membranes and lithography for microdevice production. In addition to new technological innovations utilizing conventional gamma and e-beam sources, a number of promising new applications make use of novel radiation types which include ion beams (heavy ions, light ions, highly focused microscopic beams and high-intensity pulses), soft X-rays which are focused, coherent X-rays (from a synchrotron) and e-beams which undergo scattering to generate patterns

Energy efficient LED layout optimization for near-uniform illumination

Science.gov (United States)

Ali, Ramy E.; Elgala, Hany

2016-09-01

In this paper, we consider the problem of designing energy efficient light emitting diodes (LEDs) layout while satisfying the illumination constraints. Towards this objective, we present a simple approach to the illumination design problem based on the concept of the virtual LED. We formulate a constrained optimization problem for minimizing the power consumption while maintaining a near-uniform illumination throughout the room. By solving the resulting constrained linear program, we obtain the number of required LEDs and the optimal output luminous intensities that achieve the desired illumination constraints.

Energy conservation and the residential and commercial sector

Science.gov (United States)

1975-01-01

A detailed analysis of energy conservation actions relevant to the residential and commercial sector has led to the conclusion that the potential for savings is great. The task will not be easy, however, since many of the actions require significant life style changes that are difficult to accomplish. Furthermore, many of the conservation actions cited as instant solutions to the energy crisis are those with only mid to long term potential, such as solar energy or heat pumps. Three significant conservation approaches are viable: adjusting price structure, mandating actions, and educating consumers. The first two appear to be the most feasible. But they are not without a price. Higher utility bills adversely affect the poor and the elderly on fixed incomes. Likewise, strict mandatory measures can be quite distasteful. But the effect of alternatives, such as voluntary savings accomplished through education processes, is minimal in a nation without a true conservation ethic.

Improved power quality based high brightness LED lamp driver

African Journals Online (AJOL)

user

consists of a PFC Cuk DC-DC converter which operates in continuous conduction mode (CCM) to improve the ... In proposed LED driver as shown in Figure 1, a Cuk buck boost AC-DC converter ... Design and Analysis of Proposed LED Driver.

LED licht van de toekomst

NARCIS (Netherlands)

Zeiler, W.

2009-01-01

De gloeilamp is verleden tijd, na ongeveer 125 jaar na de ontdekking door Thomas Edison valt langzaam maar zeker binnen een decennium het doek. Australië heeft de klassieke gloeilamp al in de ban gedaan en vele landen volgen deze trend. De rol van de klassieke gloeilamp wordt overgenomen door LED.

Surface defect assisted broad spectra emission from CdSe quantum dots for white LED application

Science.gov (United States)

Samuel, Boni; Mathew, S.; Anand, V. R.; Correya, Adrine Antony; Nampoori, V. P. N.; Mujeeb, A.

2018-02-01

This paper reports, broadband photoluminescence from CdSe quantum dots (QDs) under the excitation of 403 nm using fluorimeter and 403 nm CW laser excitation. The broad spectrum obtained from the colloidal quantum dots was ranges from 450 nm to 800 nm. The broadness of the spectra was attributed to the merging of band edge and defect driven emissions from the QDs. Six different sizes of particles were prepared via kinetic growth method by using CdO and elemental Se as sources of Cd and Se respectively. The particle sizes were measured from TEM images. The size dependent effect on broad emission was also studied and the defect state emission was found to be predominant in very small QDs. The defect driven emission was also observed to be redshifted, similar to the band edge emission, due to quantum confinement effect. The emission corresponding to different laser power was also studied and a linear relation was obtained. In order to study the colour characteristics of the emission, CIE chromaticity coordinate, CRI and CCT of the prepared samples were measured. It is observed that, these values were tunable by the addition of suitable intensity of blue light from the excitation source to yield white light of various colour temperatures. The broad photoluminescence spectrum of the QDs, were compared with that of a commercially available white LED. It was found that the prepared QDs are good alternatives for the phosphor in phosphor converted white LEDs, to provide good spectral tunability.

Sustainability Through Technology Licensing and Commercialization: Lessons Learned from the TRIAD Project.

Science.gov (United States)

Payne, Philip R O

2014-01-01

Ongoing transformation relative to the funding climate for healthcare research programs housed in academic and non-profit research organizations has led to a new (or renewed) emphasis on the pursuit of non-traditional sustainability models. This need is often particularly acute in the context of data management and sharing infrastructure that is developed under the auspices of such research initiatives. One option for achieving sustainability of such data management and sharing infrastructure is the pursuit of technology licensing and commercialization, in an effort to establish public-private or equivalent partnerships that sustain and even expand upon the development and dissemination of research-oriented data management and sharing technologies. However, the critical success factors for technology licensing and commercialization efforts are often unknown to individuals outside of the private sector, thus making this type of endeavor challenging to investigators in academic and non-profit settings. In response to such a gap in knowledge, this article will review a number of generalizable lessons learned from an effort undertaken at The Ohio State University to commercialize a prototypical research-oriented data management and sharing infrastructure, known as the Translational Research Informatics and Data Management (TRIAD) Grid. It is important to note that the specific emphasis of these lessons learned is on the early stages of moving a technology from the research setting into a private-sector entity and as such are particularly relevant to academic investigators interested in pursuing such activities.

Monolithic blue LED series arrays for high-voltage AC operation

Energy Technology Data Exchange (ETDEWEB)

Ao, Jin-Ping [Satellite Venture Business Laboratory, University of Tokushima, Tokushima 770-8506 (Japan); Sato, Hisao; Mizobuchi, Takashi; Morioka, Kenji; Kawano, Shunsuke; Muramoto, Yoshihiko; Sato, Daisuke; Sakai, Shiro [Nitride Semiconductor Co. Ltd., Naruto, Tokushima 771-0360 (Japan); Lee, Young-Bae; Ohno, Yasuo [Department of Electrical and Electronic Engineering, University of Tokushima, Tokushima 770-8506 (Japan)

2002-12-16

Design and fabrication of monolithic blue LED series arrays that can be operated under high ac voltage are described. Several LEDs, such as 3, 7, and 20, are connected in series and in parallel to meet ac operation. The chip size of a single device is 150 {mu}m x 120 {mu}m and the total size is 1.1 mm x 1 mm for a 40(20+20) LED array. Deep dry etching was performed as device isolation. Two-layer interconnection and air bridge are utilized to connect the devices in an array. The monolithic series array exhibit the expected operation function under dc and ac bias. The output power and forward voltage are almost proportional to LED numbers connected in series. On-wafer measurement shows that the output power is 40 mW for 40(20+20) LED array under ac 72 V. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

Case study on human α1-antitrypsin: Recombinant protein titers obtained by commercial ELISA kits are inaccurate

DEFF Research Database (Denmark)

Hansen, Henning Gram; Kildegaard, Helene Faustrup; Min Lee, Gyun

2016-01-01

Accurate titer determination of recombinant proteins is crucial for evaluating protein production cell lines and processes. Even though enzyme-linked immunosorbent assay (ELISA) is the most widely used assay for determining protein titer, little is known about the accuracy of commercially available...... ELISA kits. We observed that estimations of recombinant human ø1-antitrypsin (rø1AT) titer by Coomassie-stained SDS-PAGE gels did not correspond to previously obtained titers obtained by a commercially available ELISA kit. This prompted us to develop two independent quantification assays based...... on biolayer interferometry and reversed-phase high-performance liquid chromatography. We compared the rø1AT titer obtained by these assays with three different off-the-shelf ELISA kits and found that the ELISA kits led to inconsistent results. The data presented here show that recombinant protein titers...

Evaluation of the ability of commercial wine yeasts to form biofilms (mats) and adhere to plastic: implications for the microbiota of the winery environment.

Science.gov (United States)

Tek, Ee Lin; Sundstrom, Joanna F; Gardner, Jennifer M; Oliver, Stephen G; Jiranek, Vladimir

2018-02-01

Commercially available active dried wine yeasts are regularly used by winemakers worldwide to achieve reliable fermentations and obtain quality wine. This practice has led to increased evidence of traces of commercial wine yeast in the vineyard, winery and uninoculated musts. The mechanism(s) that enables commercial wine yeast to persist in the winery environment and the influence to native microbial communities on this persistence is poorly understood. This study has investigated the ability of commercial wine yeasts to form biofilms and adhere to plastic. The results indicate that the biofilms formed by commercial yeasts consist of cells with a combination of different lifestyles (replicative and non-replicative) and growth modes including invasive growth, bud elongation, sporulation and a mat sectoring-like phenotype. Invasive growth was greatly enhanced on grape pulp regardless of strain, while adhesion on plastic varied between strains. The findings suggest a possible mechanism that allows commercial yeast to colonise and survive in the winery environment, which may have implications for the indigenous microbiota profile as well as the population profile in uninoculated fermentations if their dissemination is not controlled. © FEMS 2018. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Private Enterprise-Led Economic Development in Sub-Saharan Africa

DEFF Research Database (Denmark)

Kuada, John Ernest

Private Enterprise-Led Development in Sub-Saharan Africa provides a novel theoretical and conceptual model to guide research into Africa's economic development. It endorses the view that private enterprise-led growth will help reduce poverty since it strengthens individuals' capacity to care...

Solution processable inverted structure ZnO-organic hybrid heterojuction white LEDs

Science.gov (United States)

Bano, N.; Hussain, I.; Soomro, M. Y.; EL-Naggar, A. M.; Albassam, A. A.

2018-05-01

Improving luminance efficiency and colour purity are the most important challenges for zinc oxide (ZnO)-organic hybrid heterojunction light emitting diodes (LEDs), affecting their large area applications. If ZnO-organic hybrid heterojunction white LEDs are fabricated by a hydrothermal method, it is difficult to obtain pure and stable blue emission from PFO due to the presence of an undesirable green emission. In this paper, we present an inverted-structure ZnO-organic hybrid heterojunction LED to avoid green emission from PFO, which mainly originates during device processing. With this configuration, each ZnO nanorod (NR) forms a discrete p-n junction; therefore, large-area white LEDs can be designed without compromising the junction area. The configuration used for this novel structure is glass/ZnO NRs/PFO/PEDOT:PSS/L-ITO, which enables the development of efficient, large-area and low-cost hybrid heterojunction LEDs. Inverted-structure ZnO-organic hybrid heterojunction white LEDs offer several improvements in terms of brightness, size, colour, external quantum efficiency and a wider applicability as compared to normal architecture LEDs.

Financial services employees' experience of peer-led and clinician-led critical incident stress debriefing following armed robberies.

Science.gov (United States)

Simms-Ellis, R; Madill, A

2001-01-01

This study investigates financial services employees' experience of critical incident stress debriefing (CISD) and their views about peers and clinicians as facilitators. Semi-structured interview accounts of four participants who had experienced both peer-led and clinician-led CISD were analyzed using grounded theory. A core category, ambivalence, permeated each interview and divided into two poles: pathologizing and normalizing. The most frequently occurring sub-category was a dislike of professionalism. Participants preferred the peer debriefer who was perceived to have more personal involvement and with whom they felt more empowered and understood. The findings suggest that the status of the debriefer as 'peer' or 'clinician' may be a crucial variable in the effectiveness of CISD and should be considered when reviewing the outcome literature.

Visual color matching system based on RGB LED light source

Science.gov (United States)

Sun, Lei; Huang, Qingmei; Feng, Chen; Li, Wei; Wang, Chaofeng

2018-01-01

In order to study the property and performance of LED as RGB primary color light sources on color mixture in visual psychophysical experiments, and to find out the difference between LED light source and traditional light source, a visual color matching experiment system based on LED light sources as RGB primary colors has been built. By simulating traditional experiment of metameric color matching in CIE 1931 RGB color system, it can be used for visual color matching experiments to obtain a set of the spectral tristimulus values which we often call color-matching functions (CMFs). This system consists of three parts: a monochromatic light part using blazed grating, a light mixing part where the summation of 3 LED illuminations are to be visually matched with a monochromatic illumination, and a visual observation part. The three narrow band LEDs used have dominant wavelengths of 640 nm (red), 522 nm (green) and 458 nm (blue) respectively and their intensities can be controlled independently. After the calibration of wavelength and luminance of LED sources with a spectrophotometer, a series of visual color matching experiments have been carried out by 5 observers. The results are compared with those from CIE 1931 RGB color system, and have been used to compute an average locus for the spectral colors in the color triangle, with white at the center. It has been shown that the use of LED is feasible and has the advantages of easy control, good stability and low cost.

Two-way visible light communication and illumination with LEDs

NARCIS (Netherlands)

Li, S.; Pandharipande, A.; Willems, F.M.J.

2017-01-01

Visible light communications (VLC) with light-emitting diodes (LEDs) has attracted applications, such as data communications, lighting control, and light interaction. In this paper, we propose a system by which two LED devices are used for two-way VLC while also providing illumination. We consider

NRaD Writing and Editorial Guidelines. Revision 1

Science.gov (United States)

1994-07-01

shall" and "The government will." THAT, WHICH That is the defining or restrictive pronoun, which is nondefining or nonrestrictive. The lawn mower that is...broken is in the garage. (tells which one) The lawn mower , which is broken, is in the garage. (used simply as a parenthetical expression between

A new bismuth-based coordination polymer as an efficient visible light responding photocatalyst under white LED irradiation

Energy Technology Data Exchange (ETDEWEB)

Huang, Ya-Jing; Zheng, Yue-Qing, E-mail: zhengyueqing@nbu.edu.cn; Wang, Jin-Jian; Zhou, Lin-Xia

2017-02-15

A new bismuth-based polymer, [Hbpe][Bi(Hpydc){sub 2}(pydc)]·H{sub 2}O (H{sub 2}pydc=pyridine-2,5-dicarboxylic acid, bpe=trans-bis(4-pyridyl) ethylene) has been hydrothermally synthesized. Transient photocurrent response and electrochemical impedance spectroscopy studies indicate that the synthesized polymer with efficient charge separation and transportation can be used as a potential photocatalyst. So we use it for the degradation of rhodamine B (RhB) dye wastewater under visible light. The comparative study on commercial Bi{sub 2}O{sub 3} shows [Hbpe][Bi(Hpydc){sub 2}(pydc)]·H{sub 2}O has the higher photocatalytic performance, with the degradation rate of 97% and 2% within 100 min for [Hbpe][Bi(Hpydc){sub 2}(pydc)]·H{sub 2}O and commercial Bi{sub 2}O{sub 3} respectively. Additionally, the five cycle reproducibility results of [Hbpe][Bi(Hpydc){sub 2}(pydc)]·H{sub 2}O implies that it can be used as a stable photocatalyst. - Graphical abstract: We report a new 1D coordination polymer [Hbpe][Bi(Hpydc){sub 2}(pydc)]·H{sub 2}O by a facile hydrothermal method. The Bi-CP shows good photoelectric property and photocatalytic activity for RhB degradation under visible white LED lamp irradiation. And the stability of the visible-light-responsive bismuth-based coordination polymer has also been examined. - Highlights: • A new Bi(III) coordination polymer is hydrothermally synthesized. • The Bi-CP shows good photoelectric and photocatalytic properties. • Bi-CP shows higher activity than the commercial Bi{sub 2}O{sub 3} for RhB degradation.

Tomographic Particle Image Velocimetry using Pulsed, High Power LED Volume Illumination

OpenAIRE

Buchmann, N. A.; Willert, C.; Soria, J.

2011-01-01

This paper investigates the use of high-power light emitting diode (LED) illumination in Particle Image Velocimetry (PIV) as an alternative to traditional laser-based illumination. The solid-state LED devices can provide averaged radiant power in excess of 10W and by operating the LEDs with short current pulses, considerably higher than in continuous operation, light pulses of sufficient energy suitable for imaging micron-sized particles can be generated. The feasibility of this LED-based ill...

Novel Carbazole Skeleton-Based Photoinitiators for LED Polymerization and LED Projector 3D Printing

Directory of Open Access Journals (Sweden)

Assi Al Mousawi

2017-12-01

Full Text Available Radical chemistry is a very convenient way to produce polymer materials. Here, an application of a particular photoinduced radical chemistry is illustrated. Seven new carbazole derivatives Cd1–Cd7 are incorporated and proposed as high performance near-UV photoinitiators for both the free radical polymerization (FRP of (methacrylates and the cationic polymerization (CP of epoxides utilizing Light Emitting Diodes LEDs @405 nm. Excellent polymerization-initiating abilities are found and high final reactive function conversions are obtained. Interestingly, these new derivatives display much better near-UV polymerization-initiating abilities compared to a reference UV absorbing carbazole (CARET 9H-carbazole-9-ethanol demonstrating that the new substituents have good ability to red shift the absorption of the proposed photoinitiators. All the more strikingly, in combination with iodonium salt, Cd1–Cd7 are likewise preferred as cationic photoinitiators over the notable photoinitiator bis(2,4,6-trimethylbenzoylphenylphosphine oxide (BAPO for mild irradiation conditions featuring their remarkable reactivity. In particular their utilization in the preparation of new cationic resins for LED projector 3D printing is envisioned. A full picture of the included photochemical mechanisms is given.

Freeform lens design for LED collimating illumination.

Science.gov (United States)

Chen, Jin-Jia; Wang, Te-Yuan; Huang, Kuang-Lung; Liu, Te-Shu; Tsai, Ming-Da; Lin, Chin-Tang

2012-05-07

We present a simple freeform lens design method for an application to LED collimating illumination. The method is derived from a basic geometric-optics analysis and construction approach. By using this method, a highly collimating lens with LED chip size of 1.0 mm × 1.0 mm and optical simulation efficiency of 86.5% under a view angle of ± 5 deg is constructed. To verify the practical performance of the lens, a prototype of the collimator lens is also made, and an optical efficiency of 90.3% with a beam angle of 4.75 deg is measured.

Forward Conduction Mode Controlled Piezoelectric Transformer-Based PFC LED Drive

DEFF Research Database (Denmark)

Roedgaard, M. S.; Weirich, M.; Andersen, M. A. E.

2013-01-01

Light-emitting diode (LED) illumination is getting more and more common; as LED's performance is rising, the price is falling and is getting competitive. Some of the challenges of ac mains supplied illumination are the requirement of power factor correction (PFC) and the competitiveness of a low...... priced market. In this paper, a new forward conduction mode (FCM) control method for piezoelectric transformer (PT)-based power converters is proposed. A PT-based LED drive facilitating passive PFC is developed, utilizing and validating the FCM control method. The drive utilizes an inductorless half...... LED drive has been developed, supplied from 230-V 50-Hz ac mains, achieving a power factor of 0.96....

Making Plans against All Odds : LED in Small Towns of the Free ...

African Journals Online (AJOL)

Since the transition to democracy, there has been an increasing emphasis on local economic development (LED) in South Africa. The LED efforts in three small municipalities of the Free State Province are examined against the international framework for. LED planning and implementation. Often, LED is limited to ...

Effect of Led Lighting Colors for Laying Japanese Quails

Directory of Open Access Journals (Sweden)

KC Nunes

Full Text Available ABSTRACT Time of exposure and light intensity rearing house may affect the performance and egg quality of laying quails. This research aimed at evaluating the live performance, egg quality, biometry of the reproductive system, and the gastrointestinal tract of Japanese quails (Coturnix coturnix japonica exposed to artificial light-emitting diodes (LED of different colors in comparison with fluorescent lamps. A total of 240 Japanese quails were distributed in completely randomized experimental design with four treatments (fluorescent lamp, and green, red, or blue LED lamps with six replicates of 10 birds each. Average egg weight and eggshell thickness were different (p0.05. The oviduct of 64-d-old hens exposed to green LED lighting was shorter (p<0.05 than those exposed to the fluorescent lamp. Red LED can be used to replace the fluorescent lamps, as they promote the same live performance, egg quality, and morphological development of the reproductive tract of laying Japanese quails.

Commercial, environmental and legislative factors that influence the implementation of fuel cells

Science.gov (United States)

Serfass, Jeffrey A.; Bergman, Michael K.; Rodenhiser, Wendy

1994-04-01

Fuel cells and other advanced electric-generation technologies have not experienced a record of successful commercialization efforts. To lower costs for these technologies, it requires substantial production volumes with a significant investment in manufacturing facilities, all dependent on developer confidence in the ultimate market. Yet, market acceptance by buyers requires an adequate demonstration of technical performance and an assurance that these lower costs can be reached. In addition to this fundamental commercialization challenge, there are significant external factors that are greatly influencing the market's (utility's) future implementation of new alternative energy-generating technologies. The factor that has possibly the greatest impact today is the public demand for environmentally benign and renewable resource technologies. There is a growing trend of involvement by consumers, regulators and intervenors in the business and utility industry that is shifting the economic playing field by which industries make resource decisions. Concerns over air pollution, global warming, acid precipitation, depletion of the ozone layer and the hazards of electromagnetic fields (EMF) from power lines, have all led to more stringent regulations and environmental mandates. The utility business environment itself is rapidly changing. Higher public expectations from energy providers and increasing competition are leading to major changes in the American utility sector. Competitive requirements to reduce the cost of utility service is leading to business decisions that provide both opportunities and problems for increased use of alternative energy-generating technologies, like fuel cells, and/or renewables, such as wind and solar photovoltaics. Bringing new energy technologies to market is very expensive and this financial burden cannot be shouldered by the market, manufacturers or federal government alone. Further, for the market to assume a key position in early

Recycling Sounds in Commercials

DEFF Research Database (Denmark)

Larsen, Charlotte Rørdam

2012-01-01

Commercials offer the opportunity for intergenerational memory and impinge on cultural memory. TV commercials for foodstuffs often make reference to past times as a way of authenticating products. This is frequently achieved using visual cues, but in this paper I would like to demonstrate how...... such references to the past and ‘the good old days’ can be achieved through sounds. In particular, I will look at commercials for Danish non-dairy spreads, especially for OMA margarine. These commercials are notable in that they contain a melody and a slogan – ‘Say the name: OMA margarine’ – that have basically...... remained the same for 70 years. Together these identifiers make OMA an interesting Danish case to study. With reference to Ann Rigney’s memorial practices or mechanisms, the study aims to demonstrate how the auditory aspects of Danish margarine commercials for frying tend to be limited in variety...

Developing a nurse-led clinic using transformational leadership.

Science.gov (United States)

Gousy, Mamood; Green, Kim

2015-03-25

Nurses are at the forefront of implementing and managing change, given constantly changing healthcare services and the increase in demand for health care. Therefore, it is important to identify the best style of leadership to engage nurses in implementing service-led improvements. This article explores the effects of transformational leadership in bringing about service-led improvements in health care, using the example of setting up a nurse-led acupuncture clinic to optimise the care of patients with chronic pain. Transformational leadership was used throughout the project - from the initial local planning, training and development, through to liaising with the appropriate staff and deciding on an evaluation strategy. Transformational leadership proved to be an effective way to engage and empower nurses and other members of the chronic pain team to enable them to achieve the project aims.

Infrared LED Array For Silicon Strip Detector Qualification

CERN Document Server

Dirkes, Guido; Hartmann, Frank; Heier, Stefan; Schwerdtfeger, Wolfgang; Waldschmitt, M; Weiler, K W; Weseler, Siegfried

2003-01-01

The enormous amount of silicon strip detector modules for the CMS tracker requires a test-sytem to allow qualification of each individual detector module and its front-end electronics within minutes. The objective is to test the detector with a physical signal. Signals are generated in the detector by illumination with lightpulses emitted by a LED at 950~nm and with a rise time of 10~ns. In order to avoid a detector moving, an array of 64 LEDs is used, overlaping the complete detector width. The total length of an array is 15~cm. The spot size of an individual LED is controlled by apertures to illuminate about 25 strips. Furthermore it is possible to simulate the high leakage current of irradiated sensors by constant illumination of the sensor. This provides an effective mean to identfy pinholes on a sensor.

Color Degradation of Textiles with Natural Dyes and of Blue Scale Standards Exposed to White LED Lamps:Evaluation of White LED Lamps for Effectiveness as Museum Lighting

Science.gov (United States)

Ishii, Mie; Moriyama, Takayoshi; Toda, Masahiro; Kohmoto, Kohtaro; Saito, Masako

White light-emitting diodes (LED) are well suited for museum lighting because they emit neither UV nor IR radiation, which damage artifacts. The color degradation of natural dyes and blue scale standards (JIS L 0841) by white LED lamps are examined, and the performance of white LED lamps for museum lighting is evaluated. Blue scale standard grades 1-6 and silk fabrics dyed with 22 types of natural dyes classified as mid to highly responsive in a CIE technical report (CIE157:2004) were exposed to five types of white LED lamps using different luminescence methods and color temperatures. Color changes were measured at each 15000 lx·hr (500 lx at fabric surface × 300 hr) interval ten times. The accumulated exposure totaled 150000 lx·hr. The data on conventional white LED lamps and previously reported white fluorescent (W) and museum fluorescent (NU) lamps was evaluated. All the white LED lamps showed lower fading rates compared with a W lamp on a blue scale grade 1. The fading rate of natural dyes in total was the same between an NU lamp (3000 K) and a white LED lamp (2869 K). However, yellow natural dyes showed higher fading rates with the white LED lamp. This tendency is due to the high power characteristic of the LED lamp around 400-500 nm, which possibly contributes to the photo-fading action on the dyes. The most faded yellow dyes were Ukon (Curcuma longa L.) and Kihada (Phellodendron amurense Rupr.), and these are frequently used in historic artifacts such as kimono, wood-block prints, and scrolls. From a conservation point of view, we need to continue research on white LED lamps for use in museum lighting.

Development of constant-power driving control for light-emitting-diode (LED) luminaire

International Nuclear Information System (INIS)

Huang, Bin-Juine; Chen, Chun-Wei; Ong, Chin-Dian; Du, Bo-Han; Hsu, Po-Chien

2013-01-01

The illumination of an LED may be affected by operating temperature even under constant-current condition. A constant-power driving technique is proposed in the present study for LED luminaire. A linear system dynamics model of LED luminaire is first derived and used in the design of the feedback control system. The PI controller was designed and tuned taking into account the control accuracy and robust properties with respect to plant uncertainty and variation of operating conditions. The control system was implemented on a microprocessor and used to control a 150W LED luminaire. The test result shows that the feedback system accurately controls the input power of LED luminaire to within 1.3 per cent error. As the ambient temperature changes from 0 to 40 °C, the LED illumination varies slightly (−1.7%) for constant-power driving, as compared to that of constant-current driving (−12%) and constant-voltage driving (+50%). The constant-power driving has revealed advantage in stabilizing the illumination of LED under large temperature variation. - Highlights: ► A constant-power driving technique is proposed for LED luminaire. ► A linear system dynamics model of LED luminaire is used in the control system design. ► The test shows that the feedback system accurately controls the input power. ► The LED illumination varies slightly (−1.7%) for constant-power driving.

Interior LED Lighting Technology. Navy Energy Technology Validation (Techval) Program

Science.gov (United States)

2015-09-01

usually on most of the time. • Consider replacing existing CFL, high-intensity discharge (HID), or halogen lamp light fixtures/ lamps with LED fixtures... lamps . What is the Technology? An LED is a semiconductor-diode that emits light when power is applied. A driver is used, much as a ballast, to...available in integrated luminaires that can be used to replace existing luminaires. LEDs are also available as direct replacement lamps for many

Efficient conceptual design for LED-based pixel light vehicle headlamps

Science.gov (United States)

Held, Marcel Philipp; Lachmayer, Roland

2017-12-01

High-resolution vehicle headlamps represent a future-oriented technology that can be used to increase traffic safety and driving comfort. As a further development to the current Matrix Beam headlamps, LED-based pixel light systems enable ideal lighting functions (e.g. projection of navigation information onto the road) to be activated in any given driving scenario. Moreover, compared to other light-modulating elements such as DMDs and LCDs, instantaneous LED on-off toggling provides a decisive advantage in efficiency. To generate highly individualized light distributions for automotive applications, a number of approaches using an LED array may be pursued. One approach is to vary the LED density in the array so as to output the desired light distribution. Another notable approach makes use of an equidistant arrangement of the individual LEDs together with distortion optics to formulate the desired light distribution. The optical system adjusts the light distribution in a manner that improves resolution and increases luminous intensity of the desired area. An efficient setup for pixel generation calls for one lens per LED. Taking into consideration the limited space requirements of the system, this implies that the luminous flux, efficiency and resolution image parameters are primarily controlled by the lens dimensions. In this paper a concept for an equidistant LED array arrangement utilizing distortion optics is presented. The paper is divided into two parts. The first part discusses the influence of lens geometry on the system efficiency whereas the second part investigates the correlation between resolution and luminous flux based on the lens dimensions.

Deadhead Trip Minimization in City Bus Transportation: A Real Life Application

Directory of Open Access Journals (Sweden)

Efendi Nasibov

2013-04-01

Full Text Available The quality of public transportation services is one of the most important performance indicators of modern urban policies for both planning and implementation aspects. Therefore, along with the size of the city, the significance of appropriate cost evaluation and optimization of all related transportation activities increases as well. One of the most important cost factors for the public transport agencies is naturally the fuel consumption of the vehicles. In this study, the attention is focused on the metropolitan bus transport service. The specific aim is to minimize a significant portion of total fuel utilization that occurs due to the so called deadhead trip or dead mileage, which is defined as the idle distance covered by the vehicle between the garage and the route terminal stops without carrying any passengers. In this study, the results of four mathematical models for minimizing the total deadhead trip distance covered in city bus services of Izmir are presented. The models vary due to the inclusion of garage capacity restrictions or operator distinction for supporting both operational and strategical decisions. All models are applied to the recent bus schedule data, which consist of 293 routes, 1,424 buses and 10 garages, for obtaining the optimal route bus-garage allocations and garage capacities. The results of the Decentralized-Capacitated model, which is appropriate for quick implementation, promise a 7.8% reduction in total dead mileage. While on the other hand, if all garage capacities can be expanded and the bus service is maintained only by one operator as modelled in the Centralized-Uncapacitated case, even a 31.4% improvement is possible in the long term. The environmental gains as well as the financial benefits to be achieved when the solutions are actually implemented, justify the practical contribution of the study.

Efficient and versatile light. LEDs save energy and open up manifold possibilities of design; Effizientes und vielseitiges Licht. LEDs sparen Energie und eroeffnen zahlreiche Designmoeglichkeiten

Energy Technology Data Exchange (ETDEWEB)

Fiebig, Michael [OSRAM Opto Semicondutors GmbH, Muenchen (Germany). Bereich Marketing und Business Development

2010-07-01

Light bulbs leave the European market step by step. These conventional light sources are too inefficient in the private and conventional sector. There are a lot of alternatives to light bulbs. But no technology will be able to save as much energy as light emitting diodes (LED) in the future. Today, these LEDs meet us in most different applications. Continuously new areas of application are opened up in order to reduce the power requirement clearly for the production of artificial light. Apart from energy conservation diodes also enable untold possibilities. In the future, light can be still more flexibly used owing to LED. LEDs are ideal light sources for planners and designers.

Design of High Efficiency Illumination for LED Lighting

OpenAIRE

Chang, Yong-Nong; Cheng, Hung-Liang; Kuo, Chih-Ming

2013-01-01

A high efficiency illumination for LED street lighting is proposed. For energy saving, this paper uses Class-E resonant inverter as main electric circuit to improve efficiency. In addition, single dimming control has the best efficiency, simplest control scheme and lowest circuit cost among other types of dimming techniques. Multiple serial-connected transformers used to drive the LED strings as they can provide galvanic isolation and have the advantage of good current distribution against de...

A new LED light source for display cases

DEFF Research Database (Denmark)

Dam-Hansen, Carsten; Petersen, Paul Michael

Abstract: We report a new LED light source suitable for illumination of gold objects. It has a variable correlated color temperature from 2760 K to 2200 K with a high color rendering index up to 97.......Abstract: We report a new LED light source suitable for illumination of gold objects. It has a variable correlated color temperature from 2760 K to 2200 K with a high color rendering index up to 97....

The Development of LED-Based Dental Light Using a Multiplanar Reflector Design

Directory of Open Access Journals (Sweden)

Chi-Chang Hsieh

2014-01-01

Full Text Available A multiplanar reflector was designed to enhance the application efficiency of light-emitting diode (LED light sources that can be employed as LED-based dental lights. This study used a high-power LED developed by Nichia, that is, a single LED capable of providing a total luminous flux of 120 lm, as the primarily light source to design and develop an LED-based dental light. This LED complies with the international standards and regulations stipulated in ISO 9680:2007. The light spots produced by the prototype were rectangular, with a length of 200 mm and a width of 100 mm. These light spots achieved maximum illumination of 12,000 lux. The use of LEDs can reduce energy consumption from 50 W to 3 W, providing an energy saving of more than 90%.

InGaN/GaN Nanowire LEDs and Lasers

KAUST Repository

Zhao, Chao

2016-01-01

The large specific surface, and the associated high density of surface states was found to limit the light output power and quantum efficiency of nanowire-array devices, despite their potential for addressing the “green-gap” and efficiency-droop issues. The phonon and carrier confinement in nanowires also led to junction heating, and reduced heat dissipation. In this paper, we will present our studies on effective surface states passivation in InGaN/GaN quantum-disks (Qdisks)-in-nanowire light-emitting diodes (LEDs) and lasers grown on silicon (Si), as well as our recent work on nanowires LEDs grown on bulk-metal, a non-conventional substrate.

Influence of interconnection on the long-term reliability of UV LED packages

Science.gov (United States)

Nieland, S.; Mitrenga, D.; Karolewski, D.; Brodersen, O.; Ortlepp, T.

2017-02-01

High power LEDs have conquered the mass market in recent years. Besides the main development focus to achieve higher productivity in the field of visible semiconductor LED processing, the wavelength range is further enhanced by active research and development in the direction of UVA / UVB / UVC. UVB and UVC LEDs are new and promising due to their numerous advantages. UV LEDs emit in a near range of one single emission peak with a width (FWHM) below 15 nm compared to conventional mercury discharge lamps and xenon sources, which show broad spectrums with many emission peaks over a wide range of wavelengths. Furthermore, the UV LED size is in the range of a few hundred microns and offers a high potential of significant system miniaturization. Of course, LED efficiency, lifetime and output power have to be increased [1]. Lifetime limiting issues of UVB/UVC-LED are the very high thermal stress in the chip resulting from the higher forward voltages (6-10 V @ 350 mA), the lower external quantum efficiency, below 10 % (most of the power disappears as heat), and the thermal resistance Rth of conventional LED packages being not able to dissipate these large amounts of heat for spreading. Beside the circuit boards and submounts which should have maximum thermal conductivity, the dimension of contacts as well as the interconnection of UV LED to the submount/package determinates the resolvable amount of heat [2]. In the paper different innovative interconnection techniques for UVC-LED systems will be discussed focused on the optimization of thermal conductivity in consideration of the assembly costs. Results on thermal simulation for the optimal contact dimensions and interconnections will be given. In addition, these theoretical results will be compared with results on electrical characterization as well as IR investigations on real UV LED packages in order to give recommendations for optimal UV LED assembly.

Luminaries-level structure improvement of LEDs for heat dissipation ...

Indian Academy of Sciences (India)

the natural convection heat transfer process of LED luminaries is simulated by compu- ... Heat dissipation has become one of the key problems limiting the large ... micro channel heat radiator, are able to reject heat efficiently, they may make LED ... convection heat transfer coefficient, for example, adopting finned surface to ...

Bridging “green gap” of LEDs: Giant light output enhancement and directional control of LEDs via embedded nano-void photonic crystals

KAUST Repository

Tsai, Yu-Lin

2015-11-23

Green LEDs do not show the same level of performance as their blue and red cousins, greatly hindering the solid-state lighting development, which is so-called “green gap”. In this work, nano-void photonic crystals (NVPCs) were fabricated to embed within the GaN/InGaN green LEDs by using epitaxial lateral overgrowth (ELO) and nano-sphere lithography techniques. The NVPCs act as an efficient scattering back-reflector to outcouple the guided and downward photons, which not only boosting light extraction efficiency of LEDs with an enhancement of 78% but also collimating the view angle of LEDs from 131.5゜to 114.0゜. This could be because the highly scattering nature of NVPCs which reduce the interference giving rise to Fabry-Perot resonance. Moreover, due to the threading dislocation suppression and strain relief by the NVPCs, the internal quantum efficiency was increased by 25% and droop behavior was reduced from 37.4% to 25.9%. The enhancement of light output power can be achieved as high as 151% at a driving current of 350 mA. Giant light output enhancement and directional control via NVPCs points the way towards a promising avenue of solid-state lighting.

Bridging “green gap” of LEDs: Giant light output enhancement and directional control of LEDs via embedded nano-void photonic crystals

KAUST Repository

Tsai, Yu-Lin; Liu, Che-Yu; Krishnan, Chirenjeevi; Lin, Da-Wei; Chu, You-Chen; Chen, Tzu-Pei; Shen, Tien-Lin; Kao, Tsung-Sheng; Charlton, Martin; Yu, Peichen; Lin, Chien-Chung; Kuo, Hao-Chung; He, Jr-Hau

2015-01-01

Green LEDs do not show the same level of performance as their blue and red cousins, greatly hindering the solid-state lighting development, which is so-called “green gap”. In this work, nano-void photonic crystals (NVPCs) were fabricated to embed within the GaN/InGaN green LEDs by using epitaxial lateral overgrowth (ELO) and nano-sphere lithography techniques. The NVPCs act as an efficient scattering back-reflector to outcouple the guided and downward photons, which not only boosting light extraction efficiency of LEDs with an enhancement of 78% but also collimating the view angle of LEDs from 131.5゜to 114.0゜. This could be because the highly scattering nature of NVPCs which reduce the interference giving rise to Fabry-Perot resonance. Moreover, due to the threading dislocation suppression and strain relief by the NVPCs, the internal quantum efficiency was increased by 25% and droop behavior was reduced from 37.4% to 25.9%. The enhancement of light output power can be achieved as high as 151% at a driving current of 350 mA. Giant light output enhancement and directional control via NVPCs points the way towards a promising avenue of solid-state lighting.

Direct battery-driven solar LED lighting using constant-power control

KAUST Repository

Huang, Bin-Juine

2012-11-01

A direct battery-driven LED lighting technique using constant-power control is proposed in the present study. A system dynamics model of LED luminaire was derived and used in the design of the feedback constant-power control system. The test result has shown that the power of 18. W and 100. W LED luminaires can be controlled accurately with error at 2-5%. A solar LED street lighting system using constant-power and dimming control was designed and built for field test in a remote area. The long-term performance was satisfactory and no any failure since the installation. Since no high-power capacitor is used in the present constant-power control circuit, a longer lifetime is expected. © 2012 Elsevier Ltd.

Materials and Designs for High-Efficacy LED Light Engines

Energy Technology Data Exchange (ETDEWEB)

Ibbetson, James [Cree, Inc., Durham, NC (United States); Gresback, Ryan [Cree, Inc., Durham, NC (United States)

2017-09-28

Cree, Inc. conducted a narrow-band downconverter (NBD) materials development and implementation program which will lead to warm-white LED light engines with enhanced efficacy via improved spectral efficiency with respect to the human eye response. New red (600-630nm) NBD materials could result in as much as a 20% improvement in warm-white efficacy at high color quality relative to conventional phosphor-based light sources. Key program innovations included: high quantum yield; narrow peak width; minimized component-level losses due to “cross-talk” and light scattering among red and yellow-green downconverters; and improved reliability to reach parity with conventional phosphors. NBD-enabled downconversion efficiency gains relative to conventional phosphors yielded an end-of-project LED light engine efficacy of >160 lm/W at room temperature and 35 A/cm2, with a correlated color temperature (CCT) of ~3500K and >90 CRI (Color Rending Index). NBD-LED light engines exhibited equivalent luminous flux and color point maintenance at >1,000 hrs. of highly accelerated reliability testing as conventional phosphor LEDs. A demonstration luminaire utilizing an NBD-based LED light engine had a steady-state system efficacy of >150 lm/W at ~3500K and >90 CRI, which exceeded the 2014 DOE R&D Plan luminaire milestone for FY17 of >150 lm/W at just 80 CRI.

Intrapartum and neonatal mortality in primary midwife-led and secondary obstetrician-led care in the Amsterdam region of the Netherlands: A retrospective cohort study

NARCIS (Netherlands)

Wiegerinck, M.M.J.; van der Goes, B.Y.; Ravelli, A.C.J.; van der Post, J.A.M.; Klinkert, J.; Brandenbarg, J.; Buist, F.C.D.; Wouters, M.G.A.J.; Tamminga, P.; de Jonge, A.; Mol, B.W.

2015-01-01

Objective: to compare intrapartum- and neonatal mortality and intervention rates in term women starting labour in primary midwife-led versus secondary obstetrician-led care. Design: retrospective cohort study. Setting: Amsterdam region of the Netherlands. Participants: women with singleton

INFLUENCE OF THE ECONOMIC AND FINANCIAL CONDITION OF STRATEGIC SHAREHOLDERS UPON THE MARKET VALUE OF COMMERCIAL BANKS IN THE POLISH BANKING SECTOR

Directory of Open Access Journals (Sweden)

Zbigniew Korzeb

2014-08-01

Full Text Available The objective of the paper is to analyse the influence of information about economic and financial problems of strategic shareholders upon the market value of commercial banks operating in the Polish banking sector. The analysis included fourteen such cases from the years 2007-2014. The results clearly indicate that investors consider the foundations of the operation of commercial banks in Poland to be very solid. Problems of strategic shareholders led to only slight depreciation of the banks’ securities quoted at the Warsaw Stock Exchange in the period directly after publication of the information. Investors decided that problems of parent companies were unlikely to threaten the stability of banks operating in the Polish banking sector.

Investigation of UV-LED Initiated Photopolymerisation of Bio-compatible HEMA

OpenAIRE

McDermott, Sharon

2008-01-01

Ultraviolet (UV) fluorescent lamps are widely used in photopolymerisation processes. However, there a number of disadvantages to these lamps, namely, their intensity varies over time and has to be constantly monitored. This thesis is concerned with the possibility of replacing these lamps with UV Light Emitting Diodes (UV-LEDs). A number of emission characteristics of both the fluorescent lamp and the UV-LEDs were measured and compared to ensure that the optical properties of the UV-LEDs were...

LED deep UV source for charge management of gravitational reference sensors

International Nuclear Information System (INIS)

Sun Kexun; Allard, Brett; Buchman, Saps; Williams, Scott; Byer, Robert L

2006-01-01

Proof mass electrical charge management is an important functionality for the ST-7-LTP technology demonstration flight and for LISA. Photoemission for charge control is accomplished by using deep ultraviolet (UV) light to excite photoelectron emission from an Au alloy. The conventional UV source is a mercury vapour lamp. We propose and demonstrate charge management using a deep UV light emitting diode (LED) source. We have acquired selected AlGaN UV LEDs, characterized their performance and successfully used them to realize charge management. The UV LEDs emit at a 257 nm central wavelength with a bandwidth of ∼12 nm. The UV power for a free-space LED is ∼120 μW, and after fibre coupling is ∼16 μW, more than sufficient for LISA applications. We have directly observed the LED UV light-induced photocurrent response from an Au photocathode and an Au-coated GRS/ST-7 proof mass. We demonstrated fast switching of UV LEDs and associated fast changes in photocurrent. This allows modulation and continuous discharge to meet stringent LISA disturbance reduction requirements. We propose and demonstrate AC charge management outside the gravitational wave signal band. Further, the megahertz bandwidth for UV LED switching allows for up to six orders of magnitude dynamic power range and a number of novel modes of operations. The UV LED based charge management system offers the advantages of small-size, lightweight, fibre-coupled operation with very low power consumption

LED-lys til ældre: Lys, trivsel og alder - Hvordan hænger det sammen?

DEFF Research Database (Denmark)

Sander, Birgit Agnes; Kessel, Line; Ahmad, Hajer

at forbedre søvnkvaliteten og dermed øge trivsel og aktivitetsniveau. Samtidig har markedet fået helt nye lyskilder som LED. De giver langt flere muligheder, end vi har været vant til med gløde- og halogenpærer og sparepærer. Glostrup Hospitals Øjenafdeling, DTU Fotonik, Statens Byggeforskningsinstitut, Gate...

36 CFR 5.6 - Commercial vehicles.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Commercial vehicles. 5.6... COMMERCIAL AND PRIVATE OPERATIONS § 5.6 Commercial vehicles. (a) The term “Commercial vehicle” as used in... used in connection with any business. (b) The use of government roads within park areas by commercial...

LED-based high-speed visible light communications

Science.gov (United States)

Chi, Nan; Shi, Meng; Zhao, Yiheng; Wang, Fumin; Shi, Jianyang; Zhou, Yingjun; Lu, Xingyu; Qiao, Liang

2018-01-01

We are seeing a growing use of light emitting diodes (LEDs) in a range of applications including lighting, TV and backlight board screen, display etc. In comparison with the traditional incandescent and fluorescent light bulbs, LEDs offer long life-space, much higher energy efficiency, high performance cost ratio and above all very fast switching capability. LED based Visible Light Communications (VLC) is an emerging field of optical communications that focuses on the part of the electromagnetic spectrum that humans can see. Depending on the transmission distance, we can divide the whole optical network into two categories, long haul and short haul. Visible light communication can be a promising candidate for short haul applications. In this paper, we outline the configuration of VLC, its unique benefits, and describe the state of the art research contributions consisting of advanced modulation formats including adaptive bit loading OFDM, carrierless amplitude and phase (CAP), pulse amplitude modulation (PAM) and single carrier Nyquist, linear equalization and nonlinear distortion mitigation based on machine learning, quasi-balanced coding and phase-shifted Manchester coding. These enabling technologies can support VLC up to 10Gb/s class free space transmission.

Finding Urban Identity through Culture-led Urban Regeneration

Directory of Open Access Journals (Sweden)

Kyu Hong Hwang

Full Text Available ABSTRACT: A city experiencing a cycle from growth to decline cannot maintain sustainable development without the type of urban identity that could be consolidated by culture-led urban regeneration. A plan for urban regeneration in a declining urban area should be practiced partially or on the whole according to the characteristics of the community. By transforming a low-value and deteriorated area into a highly valued district, the local community can simultaneously restore its social pride, revive the local economy, and realize an urban identity.Firstly, this paper examines urban decline in order to better understand urban regeneration and the need for multidisciplinary management, and also, by considering the necessity for and universal types of urban regeneration, investigates the characteristics of culture-led urban regeneration as a tool for realizing socio-economic revival and urban identity. In particular, this study suggests the action techniques and benchmarking points for urban regeneration by analyzing cases of culture-led urban regeneration in Korea. Three subjects were considered as case studies in this paper: 1 Hanok village in Jeonju city, which changed from a twilight zone to a tourist attraction; 2 Changdong district in Changwon city, which recovered from an area of declining and dark alleyways that had been the hub for arts and culture in the 1970s to become a new artist village; and 3 Cheongju city, which is being transformed from an idle industrial facility into a cultural space. This thesis suggests the implementation process of culture-led urban regeneration to find an urban identity through analysis of the causes of urban decline, the methods of regeneration, and the results of urban regeneration in the three aforementioned cases. In the conclusion section of this paper, the implementation process for culture-led urban regeneration is summarized as consisting of 5 phases: Phase 1, the diagnosis of decline; Phase 2

Side-emitting high-power LEDs and their application in illumination

Science.gov (United States)

West, Robert S.

2002-11-01

Due to the rapid increase in flux performance from High Power LED's, illumination is an exciting growth market for solid state lighting. Today a white LED is 100+ Lm per device. This is approximately an order of magnitude below the kLm metric used for illumination applications. The radiation pattern from the LED is key in increasing the usable flux resulting in improved systems optical performance. This advancement in radiation pattern will allow new market opportunities, which were not yet feasible. In the future this effect of usable lumens will become more important as the flux per package increases. The radiation pattern of the LEDs can be controlled to optimize performance, appearance, and shape of the secondary optics. This advantage is unique to LEDs and can greatly improve system performance, control, and cosmetic appeal for the application. This paper will review the side emitting lens design, the integrated performance of this technology to secondary optics and how the Luxeon side emitter enables improved performance by creating more useable lumens.

Design of LED lamps | Ashryatov | Journal of Fundamental and ...

African Journals Online (AJOL)

Design of LED lamps. ... In this paper, we study the effect of LED high brightness on the brightness of a luminaire. The nomenclature of diffusers used in the production of ... The variant of the lighting system energy efficiency increase with luminaires and linear fluorescent lamps is considered. In the proposed variant, the ...

Packaging technology of LEDs for LCD backlights

International Nuclear Information System (INIS)

Fan Manning; Liang Meng; Wang Guohong

2009-01-01

We design a package patterned with red and green emitting phosphors excited by a blue LED to emit tri-basic mixing color. For high backlight display quality, we compare several phosphors. According to our measurements, green phosphors 0752G, 0753G and red phosphor 0763R are preferred for producing a good backlight source. Compared to RGB-LED backlight units, this frame typically benefits the lighting uniformity, and can simplify the structures. It also provides higher color render and better CCT than the traditional package method of a yellow phosphor with a blue chip. However, its light efficiency needs to be further improved for the use of backlights for LCDs.

BInGaN alloys nearly lattice-matched to GaN for high-power high-efficiency visible LEDs

Science.gov (United States)

Williams, Logan; Kioupakis, Emmanouil

2017-11-01

InGaN-based visible light-emitting diodes (LEDs) find commercial applications for solid-state lighting and displays, but lattice mismatch limits the thickness of InGaN quantum wells that can be grown on GaN with high crystalline quality. Since narrower wells operate at a higher carrier density for a given current density, they increase the fraction of carriers lost to Auger recombination and lower the efficiency. The incorporation of boron, a smaller group-III element, into InGaN alloys is a promising method to eliminate the lattice mismatch and realize high-power, high-efficiency visible LEDs with thick active regions. In this work, we apply predictive calculations based on hybrid density functional theory to investigate the thermodynamic, structural, and electronic properties of BInGaN alloys. Our results show that BInGaN alloys with a B:In ratio of 2:3 are better lattice matched to GaN compared to InGaN and, for indium fractions less than 0.2, nearly lattice matched. Deviations from Vegard's law appear as bowing of the in-plane lattice constant with respect to composition. Our thermodynamics calculations demonstrate that the solubility of boron is higher in InGaN than in pure GaN. Varying the Ga mole fraction while keeping the B:In ratio constant enables the adjustment of the (direct) gap in the 1.75-3.39 eV range, which covers the entire visible spectrum. Holes are strongly localized in non-bonded N 2p states caused by local bond planarization near boron atoms. Our results indicate that BInGaN alloys are promising for fabricating nitride heterostructures with thick active regions for high-power, high-efficiency LEDs.

Commercial off-the-shelf software dedication process based on the commercial grade survey of supplier

International Nuclear Information System (INIS)

Kim, J. Y.; Lee, J. S.; Chon, S. W.; Lee, G. Y.; Park, J. K.

2000-01-01

Commercial Off-The-Shelf(COTS) software dedication process can apply to a combination of methods like the hardware commercial grade item dedication process. In general, these methods are : methods 1(special test and inspection), method 2(commercial grade survey of supplier), method 3(source verification), and method 4(acceptance supplier/item performance record). In this paper, the suggested procedure-oriented dedication process on the basis of method 2 for COTS software is consistent with EPRI/TR-106439 and NUREG/CR-6421 requirements. Additional tailoring policy based on code and standards related to COTS software may be also founded in the suggested commercial software dedication process. Suggested commercial software dedication process has been developed for a commercial I and C software dedication who performs COTS qualification according to the dedication procedure

Head-mounted LED for optogenetic experiments of freely-behaving animal

Science.gov (United States)

Kwon, Ki Yong; Gnade, Andrew G.; Rush, Alexander D.; Patten, Craig D.

2016-03-01

Recent developments in optogenetics have demonstrated the ability to target specific types of neurons with sub-millisecond temporal precision via direct optical stimulation of genetically modified neurons in the brain. In most applications, the beam of a laser is coupled to an optical fiber, which guides and delivers the optical power to the region of interest. Light emitting diodes (LEDs) are an alternative light source for optogenetics and they provide many advantages over a laser based system including cost, size, illumination stability, and fast modulation. Their compact size and low power consumption make LEDs suitable light sources for a wireless optogenetic stimulation system. However, the coupling efficiency of an LED's output light into an optical fiber is lower than a laser due to its noncollimated output light. In typical chronic optogenetic experiment, the output of the light source is transmitted to the brain through a patch cable and a fiber stub implant, and this configuration requires two fiber-to-fiber couplings. Attenuation within the patch cable is potential source of optical power loss. In this study, we report and characterize a recently developed light delivery method for freely-behaving animal experiments. We have developed a head-mounted light source that maximizes the coupling efficiency of an LED light source by eliminating the need for a fiber optic cable. This miniaturized LED is designed to couple directly to the fiber stub implant. Depending on the desired optical power output, the head-mounted LED can be controlled by either a tethered (high power) or battery-powered wireless (moderate power) controller. In the tethered system, the LED is controlled through 40 gauge micro coaxial cable which is thinner, more flexible, and more durable than a fiber optic cable. The battery-powered wireless system uses either infrared or radio frequency transmission to achieve real-time control. Optical, electrical, mechanical, and thermal

LED photochemotherapy against Staphylococcus aureus: an in vitro study

Science.gov (United States)

de Oliveira, Susana C. P. S.; Monteiro, Juliana S. C.; Pires-Santos, Gustavo M.; Sampaio, Fernando José Pires; Soares, Luiz Guilherme P.; Soares, Amanda P.; Pinheiro, Antônio L. B.

2018-02-01

Bacterial resistance to antibiotics is reality and need for alternative treatments is urgent. The aim of this work was to evaluate, in vitro, the effect of LED photochemotherapy on Staphylococcus aureus (ATCC 23529) using 25 μg / mL of phenothiazine compound combined with LED light (λ632 +/- 2ηm) using 12 J/cm2 energy density. The experiments were carried out in triplicate and the samples were divided into groups: Control, Irradiated (treated only with light), Photosensitizer (treated only in the presence of the dye), LED-Photochemotherapy (treatment with light associated with dye). Counts of the colony forming units and the data obtained were statistically analyzed (ANOVA, Tukey's test, p<0.05). The present study demonstrated that the efficacy of LED-Photochemotherapy as the use of 25 μg/mL x 12 J/cm2 caused 91.57 % of inhibition of bacterial growth. It is concluded that using energy density of 12 J/cm2 associated to 25 μg/mL caused high in vitro inhibition of S. aureus.

Null bactericidal effect of ultraviolet radiation emitted by LEDs.

Directory of Open Access Journals (Sweden)

Francisco Alcántara Muñoz

2016-11-01

Full Text Available This research has aimed to assess the bactericidal effect of ultraviolet light emitted by LEDS on the growth on Petri dishes of microorganisms whose legal limits in foods have been established. An electrically fed apparatus has been designed with precise timing and a camera to prevent light spillage, in which two ultraviolet radiation emission devices were connected by LED technology at different wavelengths: through an array of LEDS emitting at around 350nm, and a single specific emission LED at 280nm. 1000 cfu of E. Coli and S. aureus sown on PCA were used as prototypes of gram negative and positive bacteria, respectively, onto which ultraviolet light was radiated at different time intervals, by means of both devices, with the whole experiment being carried out in triplicate . In none of the three series of treatments at the two wavelengths were reductions in microbial growth observed. The series of sowings on PCA were done on unseeded plates in order to be able to discard the likelihood of subsequent recontamination.

Heterostructures for Increased Quantum Efficiency in Nitride LEDs

Energy Technology Data Exchange (ETDEWEB)

Davis, Robert F. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

2010-09-30

Task 1. Development of an advanced LED simulator useful for the design of efficient nitride-based devices. Simulator will contain graphical interface software that can be used to specify the device structure, the material parameters, the operating conditions and the desired output results. Task 2. Theoretical and experimental investigations regarding the influence on the microstructure, defect concentration, mechanical stress and strain and IQE of controlled changes in the chemistry and process route of deposition of the buffer layer underlying the active region of nitride-based blue- and greenemitting LEDs. Task 3. Theoretical and experimental investigations regarding the influence on the physical properties including polarization and IQE of controlled changes in the geometry, chemistry, defect density, and microstructure of components in the active region of nitride-based blue- and green-emitting LEDs. Task 4. Theoretical and experimental investigations regarding the influence on IQE of novel heterostructure designs to funnel carriers into the active region for enhanced recombination efficiency and elimination of diffusion beyond this region. Task 5. Theoretical and experimental investigations regarding the influence of enhanced p-type doping on the chemical, electrical, and microstructural characteristics of the acceptor-doped layers, the hole injection levels at Ohmic contacts, the specific contact resistivity and the IQE of nitride-based blue- and green-emitting LEDs. Development and optical and electrical characterization of reflective Ohmic contacts to n- and p-type GaN films.

A Lifetime Prediction Method for LEDs Considering Real Mission Profiles

DEFF Research Database (Denmark)

Qu, Xiaohui; Wang, Huai; Zhan, Xiaoqing

2017-01-01

operations due to the varying operational and environmental conditions during the entire service time (i.e., mission profiles). To overcome the challenge, this paper proposes an advanced lifetime prediction method, which takes into account the field operation mission profiles and also the statistical......The Light-Emitting Diode (LED) has become a very promising alternative lighting source with the advantages of longer lifetime and higher efficiency than traditional ones. The lifetime prediction of LEDs is important to guide the LED system designers to fulfill the design specifications...... properties of the life data available from accelerated degradation testing. The electrical and thermal characteristics of LEDs are measured by a T3Ster system, used for the electro-thermal modeling. It also identifies key variables (e.g., heat sink parameters) that can be designed to achieve a specified...

Walk the Talk. Integrated Sustainability Initiative

Energy Technology Data Exchange (ETDEWEB)

Sagebiel, John [Univ. of Nevada, Reno, NV (United States)

2014-09-30

The overall objective of this project was to demonstrate, through a series of real-world applications of existing technology, the benefits to the University of Nevada, Reno and the community, of various sustainability efforts. The project was very successful and has stimulated the Campus to take on more projects after seeing the successes of those initial ones funded through this project. The three areas of this work could broadly be described as energy efficiency, renewable energy and recycling. Under the first project, the campus did several projects replacing or changing heating and cooling systems, using state funding. The DOE funding initially funded the replacement of lights in one campus parking garage with LED lights. Subsequently, the campus facilities group recognized how effective this was and leveraged funds to do the other two garages. Similarly with the renewable energy project, once the first system was installed and working well, the campus committed funds to more than double that system. Lastly, the recycling efforts expanded the use and awareness on campus and led the campus to begin using a single-stream recycling program once it became available in this area, hopefully leading to more participation by the campus community. Thus, overall the project areas each did what they were intended to do, which was to demonstrate the usefulness of these sustainability programs and thus encourage the campus to do more. All this great work helps the campus’ goals overall, but without additional effort would not reach beyond the campus. This was the objective of the education and outreach effort. The combination of events, websites, and videos enabled us to reach many key decision makers and at the same time provide a long-term presence on the web that we can use to further educate people. The overall goals were met or exceeded and will continue to pay dividends into the future.

Intrapartum and neonatal mortality in primary midwife-led and secondary obstetrician-led care in the Amsterdam region of the Netherlands: A retrospective cohort study

NARCIS (Netherlands)

Wiegerinck, M. M. J.; van der Goes, B. Y.; Ravelli, A. C. J.; van der Post, J. A. M.; Klinkert, J.; Brandenbarg, J.; Buist, F. C. D.; Wouters, M. G. A. J.; Tamminga, P.; de jonge, A.; Mol, B. W.

2015-01-01

To compare intrapartum- and neonatal mortality and intervention rates in term women starting labour in primary midwife-led versus secondary obstetrician-led care. Retrospective cohort study. Amsterdam region of the Netherlands. Women with singleton pregnancies who gave birth beyond 37+0 weeks

The characterization of an economic and portable LED-based photoacoustic imaging system to facilitate molecular imaging.

Science.gov (United States)

Hariri, Ali; Lemaster, Jeanne; Wang, Junxin; Jeevarathinam, AnanthaKrishnan S; Chao, Daniel L; Jokerst, Jesse V

2018-03-01

Photoacoustic imaging (PAI) is a non-invasive, high-resolution hybrid imaging modality that combines optical excitation and ultrasound detection. PAI can image endogenous chromophores (melanin, hemoglobin, etc.) and exogenous contrast agents in different medical applications. However, most current equipment uses sophisticated and complicated OPO lasers with tuning and stability features inconsistent with broad clinical deployment. As the number of applications of PAI in medicine increases, there is an urgent need to make the imaging equipment more compact, portable, and affordable. Here, portable light emitting diode - based photoacoustic imaging (PLED-PAI) was introduced and characterized in terms of system specifications, light source characterizations, photoacoustic spatial/temporal resolution, and penetration. The system uses two LED arrays attached to the sides of a conventional ultrasound transducer. The LED pulse repetition rate is tunable between 1 K Hz, 2 K Hz, 3 K Hz, and 4 K Hz. The axial resolution was 0.268 mm, and the lateral resolution was between 0.55 and 0.59 mm. The system could detect optical absorber (pencil lead) at a depth of 3.2 cm and the detection limits of indocyanine green (ICG) and methylene blue (MB) were 9 μM and 0.78 mM. In vivo imaging of labeled human mesenchymal stem cells was achieved to confirm compatibility with small animal imaging. The characterization we report here may have value to other groups evaluating commercially available photoacoustic imaging equipment.

Site status monitoring report for underground storage tanks 1219-U, 1222-U, 2082-U, and 2068-U at the Rust Garage Facility, Buildings 9720-15 and 9754-1, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee, Facility ID No. 0-010117

International Nuclear Information System (INIS)

1994-10-01

The purpose of this document is to provide hydrogeologic, geochemical, and vapor monitoring data required for site status monitoring of underground storage tanks (UST) 1219-U, 1222-U, 2082-U, and 2068-U at the Rust Garage Facility. Comprehensive monitoring was conducted at the site in May 1994 as part of a Monitoring Only program approved by Tennessee Department of Environment and Conservation (TDEC) based on review and approval of Site Ranking. This document presents the results of the first semiannual site status monitoring, which was conducted in September 1994. Site status monitoring and preparation of this report have been conducted in accordance with the requirements of the TDEC Rule 1200-1-15, the TDEC UST Reference Handbook, Second Edition, and direction from TDEC. This document is organized into three sections. Section 1 presents introductory information relative to the site including regulatory initiative and a site description. Section 2 includes the results of sampling of monitoring wells GW-508, GW-631, GW-632, and GW-634. Section 3 presents data from vapor monitoring conducted in subsurface utilities present at the site

Estudo morfométrico da terapia LED de baixa potência em tendinite de ratos Morphometric study of low power LED therapy tendonitis in rats

Directory of Open Access Journals (Sweden)

José Mário Nunes da Silva

2011-12-01

Full Text Available A terapia LED de baixa potência possui efeitos analgésico e antiinflamatório. O objetivo desse estudo foi analisar a ação da terapia com LED de baixa potência na reparação tendínea por meio de histologia e histomorfometria. Foram usados 25 ratos Wistar, de 220 a 250 g, divididos em três grupos experimentais avaliados no 7º e 14º dia: A, tendinite induzida sem tratamento; B, tendinite induzida tratada com LED de baixa potência, densidade de energia 4 J/cm² por 120 segundos; e C, sem indução de tendinite. A histomorfometria mostrou-se altamente significativa (p0,05. As análises histológica e histomorfométrica demonstraram qualitativo e quantitativo aumento no número de fibroblastos aos sete dias de tratamento, e das fibras colágenas, aos 14 dias, para grupo tratado com LED de baixa potência em relação ao grupo sadio (C. O mesmo não foi percebido quando relacionado ao grupo tendinite (A14.The low power LED therapy has analgesic and anti-inflammatory effects. The objective of this study was to analyze the action of therapy with low power LED on the tendon repair, using histology and histomorphometry. Were used 25 Wistar rats, with 220 to 250 g, divided into three experimental groups (7 and 14 days: A7 and A14 induced tendonitis without treatment; B7 and B14, induced tendinitis treated with LED low power density energy 4 J /cm² for 120 seconds; and C, without induction of tendinitis. Histomorphometry was highly significant (p 0.05. Histology and histomorphometry analysis demonstrated qualitative and quantitative increase in the number of fibroblasts to seven days of treatment, and collagen fibers at 14 days for the group treated with LED low power compared to the healthy group (C. But it is unclear even when related to the tendinitis group (A14.

Microbial UV fluence-response assessment using a novel UV-LED collimated beam system.

Science.gov (United States)

Bowker, Colleen; Sain, Amanda; Shatalov, Max; Ducoste, Joel

2011-02-01

A research study has been performed to determine the ultraviolet (UV) fluence-response of several target non-pathogenic microorganisms to UV light emitting diodes (UV-LEDs) by performing collimated beam tests. UV-LEDs do not contain toxic mercury, offer design flexibility due to their small size, and have a longer operational life than mercury lamps. Comsol Multiphysics was utilized to create an optimal UV-LED collimated beam design based on number and spacing of UV-LEDs and distance of the sample from the light source while minimizing the overall cost. The optimized UV-LED collimated beam apparatus and a low-pressure mercury lamp collimated beam apparatus were used to determine the UV fluence-response of three surrogate microorganisms (Escherichia coli, MS-2, T7) to 255 nm UV-LEDs, 275 nm UV-LEDs, and 254 nm low-pressure mercury lamps. Irradiation by low-pressure mercury lamps produced greater E. coli and MS-2 inactivation than 255 nm and 275 nm UV-LEDs and similar T7 inactivation to irradiation by 275 nm UV-LEDs. The 275 nm UV-LEDs produced more efficient T7 and E. coli inactivation than 255 nm UV-LEDs while both 255 nm and 275 nm UV-LEDs produced comparable microbial inactivation for MS-2. Differences may have been caused by a departure from the time-dose reciprocity law due to microbial repair mechanisms. Copyright © 2010 Elsevier Ltd. All rights reserved.

A high-performance stand-alone solar PV power system for LED lighting

KAUST Repository

Huang, B. J.

2010-06-01

The present study developed a high-performance solar PV power technology for the LED lighting of a solar home system. The nMPPO (near-Maximum-Power- Point- Operation) design is employed in system design to eliminate MPPT. A feedback control system using pulse width modulation (PWM) technique was developed for battery charging control which can increase the charging capacity by 78%. For high-efficiency lighting, the LED is directly driven by battery using a PWM discharge control to eliminate a DC/DC converter. Two solar-powered LED lighting systems (50W and 100W LED) were built. The long-term outdoor tests have shown that the loss of load probability for full-night lighting requirement is zero for 50W LED and 3.6% for 100W LED. © 2010 IEEE.

Performance of GaN-Based LEDs with Nanopatterned Indium Tin Oxide Electrode

Directory of Open Access Journals (Sweden)

Zhanxu Chen

2016-01-01

Full Text Available The indium tin oxide (ITO has been widely applied in light emitting diodes (LEDs as the transparent current spreading layer. In this work, the performance of GaN-based blue light LEDs with nanopatterned ITO electrode is investigated. Periodic nanopillar ITO arrays are fabricated by inductive coupled plasma etching with the mask of polystyrene nanosphere. The light extraction efficiency (LEE of LEDs can be improved by nanopatterned ITO ohmic contacts. The light output intensity of the fabricated LEDs with nanopatterned ITO electrode is 17% higher than that of the conventional LEDs at an injection current of 100 mA. Three-dimensional finite difference time domain simulation matches well with the experimental result. This method may serve as a practical approach to improving the LEE of the LEDs.

Implementation and Test of a LED-Based Lamp for a Lighthouse

Directory of Open Access Journals (Sweden)

Luca Mercatelli

2014-01-01

Full Text Available A novel sustainable source was developed for an existing Italian lighthouse, exploiting the light emitting diode (LED technology and the norms evolution. The research work started with the optical design of the device, while this work concerns the realization, installation, and test of the new LED lamp. The lamp recombines multiple separated LEDs, realizing a quasipunctual localized source. After installation in the lighthouse, specific photometric tests verified that the proposed power-saving source satisfied the illumination requirements of the marine signaling norms. The advantages of the LED-based lamp are reduced energy consumption, enhanced efficiency, longer life, decreased faults, slower aging, and lower maintenance costs. The obtained LED signalling device is more durable and reliable. In the future the application of these power-saving long-life sources could be extended to other maritime signaling devices or to other traffic signs.

Design of a Multi-Color Lamp Using High Brightness RGB LEDs

Energy Technology Data Exchange (ETDEWEB)

Song, S.B.; Kang, S.H.; Yeo, I.S. [Chonnam National University, Kwangju (Korea)

2003-02-01

This paper proposes the design of a multi-color lamp using high brightness RGB LEDs for color variation. Appropriate number of RGB LEDs is so chosen according to the color mixing theory that the overall LEDs represent a color temperature of 6500K. Also, the chosen RGB LEDs are suitably arranged by using an optical design program. The lamp has an internal controller circuit, so it can be directly connected to the existing incandescent lamp socket. It's main body is comprised of two PCB layers. The upper layer contains 44 LEDs and the lower one has a simple microcontroller-based PWM control circuit. The lamp has functions of both ON/OFF control and PWM control, and enables color variation of over 100,000 colors and of more than 10 patterns. (author). 7 refs., 11 figs., 3 tabs.

Evaluation of a nurse-led haemophilia counselling service.

LENUS (Irish Health Repository)

O'Shea, Eadaoln

2012-01-01

Genetic counselling and testing for females with a family history of haemophilia has long been advocated. However, there is little research in regard to clients\\' satisfaction with the existing counselling models in haemophilia, and in particular with nurse-led clinics. The purpose of this study was to evaluate whether clients were satisfied with a nurse-led carrier testing clinic and counselling service. A retrospective quantitative study of clients\\' satisfaction and perceived knowledge was undertaken using an anonymous questionnaire. A sample of 42 women who had attended the clinic in the last 12 months was identified. The response rate for the study was 71% (n = 30).Two thirds of the respondents were 35 years of age or younger, 93% had a family history of haemophilia and 56% were diagnosed as carriers. Perceived understanding and knowledge increased significantly between the first and second appointments (p < 0.001). Overall, the study identified a high level of client satisfaction with the nurse-led carrier testing clinic and counselling service.

Blue laser diode (LD) and light emitting diode (LED) applications

International Nuclear Information System (INIS)

Bergh, Arpad A.

2004-01-01

The family of blue LEDs, edge emitting and surface emitting lasers, enable a number of applications. Blue lasers are used in digital applications such as optical storage in high density DVDs. The resolution of the spot size and hence the storage density is diffraction limited and is inversely proportional to the square of the wavelength of the laser. Other applications include printing, optical scanners, and high-resolution photo-lithography. As light emitters, blue LEDs are used for signaling and in direct view large area emissive displays. They are also making inroads into signage and LCD back-lighting, mobile platforms, and decorative accent lighting in curtains, furniture, etc. Blue LEDs produce white light either with phosphor wavelength converters or in combination with red and green LEDs. The full potential of LED light sources will require three devices to enable complete control over color and intensity. Sensing and medical/bio applications have a major impact on home security, on monitoring the environment, and on health care. New emerging diagnostic and therapeutic applications will improve the quality and reduce the cost of health care. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Blue laser diode (LD) and light emitting diode (LED) applications

Energy Technology Data Exchange (ETDEWEB)

Bergh, Arpad A [Optoelectronics Industry Development Association (OIDA), 1133 Connecticut Avenue, NW, Suite 600, Washington, DC 20036-4329 (United States)

2004-09-01

The family of blue LEDs, edge emitting and surface emitting lasers, enable a number of applications. Blue lasers are used in digital applications such as optical storage in high density DVDs. The resolution of the spot size and hence the storage density is diffraction limited and is inversely proportional to the square of the wavelength of the laser. Other applications include printing, optical scanners, and high-resolution photo-lithography. As light emitters, blue LEDs are used for signaling and in direct view large area emissive displays. They are also making inroads into signage and LCD back-lighting, mobile platforms, and decorative accent lighting in curtains, furniture, etc. Blue LEDs produce white light either with phosphor wavelength converters or in combination with red and green LEDs. The full potential of LED light sources will require three devices to enable complete control over color and intensity. Sensing and medical/bio applications have a major impact on home security, on monitoring the environment, and on health care. New emerging diagnostic and therapeutic applications will improve the quality and reduce the cost of health care. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Notes on LED Installations in Street Illumination

Directory of Open Access Journals (Sweden)

Elisabeta Spunei

2014-09-01

Full Text Available The paper presents a study made on choosing LED street lighting installations, such that the quality requirements for exterior artificial lighting are fulfilled. We analyze two types of LED street lighting installations from a technical point of view, together with lighting level and brightness values obtained during the measurements. Following on the field measurements, the lighting quality parameters are calculated, and, for the lighting installation with the best performance, optimal mounting suggestions are made. The optimal quality parameters are calculated by simulations using the Dialux software. The same software and the same light sources we also compute an optimal street lighting by determining the size of the installation that provides the best lighting parameter values.

The High-efficiency LED Driver for Visible Light Communication Applications.

Science.gov (United States)

Gong, Cihun-Siyong Alex; Lee, Yu-Chen; Lai, Jyun-Liang; Yu, Chueh-Hao; Huang, Li Ren; Yang, Chia-Yen

2016-08-08

This paper presents a LED driver for VLC. The main purpose is to solve the low data rate problem used to be in switching type LED driver. The GaN power device is proposed to replace the traditional silicon power device of switching LED driver for the purpose of increasing switching frequency of converter, thereby increasing the bandwidth of data transmission. To achieve high efficiency, the diode-connected GaN power transistor is utilized to replace the traditional ultrafast recovery diode used to be in switching type LED driver. This work has been experimentally evaluated on 350-mA output current. The results demonstrate that it supports the data of PWM dimming level encoded in the PPM scheme for VLC application. The experimental results also show that system's efficiency of 80.8% can be achieved at 1-Mb/s data rate.

MEDIATION CLAUSE IN COMMERCIAL CONTRACTS (THE ADVANTAGES OF MEDIATION CLAUSE IN COMMERCIAL CONTRACTS

Directory of Open Access Journals (Sweden)

Claudiu Florinel Augustin Ignat

2013-11-01

Full Text Available It often happens that the end of the contracts to be existing commercial relationships and a new contract has already intuitu personae character. But not always the case, that those who enter into legal commercial forcing consideration to the benefits and under commercial contracts, know the dealer or individual that established commercial relations. These traders resort to contractual conditions which states precisely the extent of the obligations assumed by each party, setting rules, deadlines, penalties and even ways of interpretation of contracts. Contracting Parties, namely traders aware that the law is the contract parties by special caluze invest ( to settle disputes concerning the interpretation or punishment for failure and even termination obligations tribunalule arbitration courts or the territorial and material .

LED-Based High-Voltage Lines Warning System

Directory of Open Access Journals (Sweden)

Eldar MUSA

2013-04-01

Full Text Available LED-based system, running with the current of high-voltage lines and converting the current flowing through the line into the light by using a toroid transformer, has been developed. The transformer’s primary winding is constituted by the high voltage power line. Toroidal core consists of two equal parts and the secondary windings are evenly placed on these two parts. The system is mounted on the high-voltage lines as a clamp. The secondary winding ends are connected in series by the connector on the clamp. LEDs are supplied by the voltage at the ends of secondary. Current flowing through highvoltage transmission lines is converted to voltage by the toroidal transformer and the light emitting LEDs are supplied with this voltage. The theory of the conversion of the current flowing through the line into the light is given. The system, running with the current of the line and converting the current into the light, has been developed. System has many application areas such as warning high voltage lines (warning winches to not hinder the high-voltage lines when working under the lines, warning planes to not touch the high-voltage lines, remote measurement of high-voltage line currents, and local illumination of the line area

Development of constant-power driving control for light-emitting-diode (LED) luminaire

KAUST Repository

Huang, Bin-Juine

2013-01-01

The illumination of an LED may be affected by operating temperature even under constant-current condition. A constant-power driving technique is proposed in the present study for LED luminaire. A linear system dynamics model of LED luminaire is first derived and used in the design of the feedback control system. The PI controller was designed and tuned taking into account the control accuracy and robust properties with respect to plant uncertainty and variation of operating conditions. The control system was implemented on a microprocessor and used to control a 150W LED luminaire. The test result shows that the feedback system accurately controls the input power of LED luminaire to within 1.3 per cent error. As the ambient temperature changes from 0 to 40 °C, the LED illumination varies slightly (-1.7%) for constant-power driving, as compared to that of constant-current driving (-12%) and constant-voltage driving (+50%). The constant-power driving has revealed advantage in stabilizing the illumination of LED under large temperature variation. © 2012 Elsevier Ltd. All rights reserved.

Direct battery-driven solar LED lighting using constant-power control

KAUST Repository

Huang, Bin-Juine; Chen, Chun-Wei; Hsu, Po-Chien; Tseng, Wei-Min; Wu, Min-Sheng

2012-01-01

A direct battery-driven LED lighting technique using constant-power control is proposed in the present study. A system dynamics model of LED luminaire was derived and used in the design of the feedback constant-power control system. The test result

Photoelectrochemical liftoff of LEDs grown on freestanding c-plane GaN substrates

KAUST Repository

Hwang, David

2016-09-23

We demonstrate a thin-film flip-chip (TFFC) process for LEDs grown on freestanding c-plane GaN substrates. LEDs are transferred from a bulk GaN substrate to a sapphire submount via a photoelectrochemical (PEC) undercut etch. This PEC liftoff method allows for substrate reuse and exposes the N-face of the LEDs for additional roughening. The LEDs emitted at a wavelength of 432 nm with a turn on voltage of ~3 V. Etching the LEDs in heated KOH after transferring them to a sapphire submount increased the peak external quantum efficiency (EQE) by 42.5% from 9.9% (unintentionally roughened) to 14.1% (intentionally roughened).

Light emitting diodes (LED): applications in forest and native plant nurseries

Science.gov (United States)

Thomas D. Landis; Jeremiah R. Pinto; R. Kasten Dumroese

2013-01-01

It was quotes like this that made us want to learn more about light emitting diodes (LED). Other than knowing that LEDs were the latest innovation in artificial lighting, we knew that we had a lot to learn. So we started by reviewing some of the basics. The following review is a brief synopsis of how light affects plants and some discussion about LED lighting. If you...

36 CFR 271.4 - Commercial license.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Commercial license. 271.4... BEARâ SYMBOL § 271.4 Commercial license. (a) The Chief may authorize the commercial manufacture... a use or royalty charge which is reasonably related to the commercial enterprise has been...

27 CFR 10.21 - Commercial bribery.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Commercial bribery. 10.21 Section 10.21 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS COMMERCIAL BRIBERY Commercial Bribery § 10.21 Commercial bribery. It is...

Traditional versus commercial food processing techniques - A comparative study based on chemical analysis of selected foods consumed in rural Zimbabwe.

Directory of Open Access Journals (Sweden)

Abraham I. C. Mwadiwa

2012-01-01

Full Text Available With the advent of industrialisation, food processors are constantly looking for ways to cut costs, increase production and maximise profits at the expense of quality. Commercial food processors have since shifted their focus from endogenous ways of processing food to more profitable commercial food processing techniques. The aim of this study was to investigate the holistic impact of commercial food processing techniques on nutrition by comparing commercially (industrially processed food products and endogenously processed food products through chemical analysis of selected foods. Eight food samples which included commercially processed peanut butter, mealie-meal, dried vegetables (mufushwa and rice and endogenously processed peanut butter, mealie-meal, dried vegetables (mufushwa and rice were randomly sampled from rural communities in the south-eastern and central provinces of Zimbabwe. They were analysed for ash, zinc, iron, copper, magnesium, protein, fat, carbohydrates, energy, crude fibre, vitamin C and moisture contents. The results of chemical analysis indicate that endogenously processed mealie-meal, dried vegetables and rice contained higher ash values of 2.00g/100g, 17.83g/100g, and 3.28g/100g respectively than commercially processed mealie-meal, dried vegetables and rice, which had ash values of 1.56g/100g, 15.25g/100g and 1.46g/100g respectively. The results also show that endogenously processed foods have correspondingly higher iron, zinc and magnesium contents and, on the whole, a higher protein content. The results also indicate that commercially processed foods have higher fat and energy contents. The result led to the conclusion that the foods are likely to pose a higher risk of causing adverse conditions to health, such as obesity and cardiovascular diseases to susceptible individuals. Based on these findings, it can, therefore, be concluded that endogenously processed foods have a better nutrient value and health implications

CMOS-compatible plenoptic detector for LED lighting applications.

Science.gov (United States)

Neumann, Alexander; Ghasemi, Javad; Nezhadbadeh, Shima; Nie, Xiangyu; Zarkesh-Ha, Payman; Brueck, S R J

2015-09-07

LED lighting systems with large color gamuts, with multiple LEDs spanning the visible spectrum, offer the potential of increased lighting efficiency, improved human health and productivity, and visible light communications addressing the explosive growth in wireless communications. The control of this "smart lighting system" requires a silicon-integrated-circuit-compatible, visible, plenoptic (angle and wavelength) detector. A detector element, based on an offset-grating-coupled dielectric waveguide structure and a silicon photodetector, is demonstrated with an angular resolution of less than 1° and a wavelength resolution of less than 5 nm.

New insights into consumer-led food product development

DEFF Research Database (Denmark)

Costa, Ana I. A.; Jongen, W.M.F.

2006-01-01

industry are described. Contrary to previous optimistic views, it is put forward that without significant changes taking place in the mindset of the organizations involved in Europe's food R&D, the way forward for consumer-led innovation strategies in the agri-business sector will be long and hard.......This paper builds upon a review of relevant marketing, consumer science and innovation management literature to introduce the concept of consumer-led new product development and describe its main implementation stages. The potential shortcomings of this concept's application in European food...

Enabling factors for the improvement of nitride-based LED efficiency

International Nuclear Information System (INIS)

Laubsch, Ansgar; Bergbauer, Werner; Sabathil, Matthias; Peter, Matthias; Meyer, Tobias; Bruederl, Georg; Linder, Norbert; Streubel, Klaus; Oberschmid, Raimund; Hahn, Berthold; Wagner, Joachim

2008-01-01

Recent progress in the epitaxial growth of LEDs with InGaN/GaN quantum-well heterostructures has led to a significant enhancement of output power. In this talk, we will discuss the mechanisms limiting the devices' internal efficiency and identify enabling factors for further improvements. We compare samples with different Indium content as well as different design of the active layer. Although heteroepitaxial growth of GaN on sapphire generates high defect densities, non-radiative defect-related Shockley-Read-Hall recombination does not seem to substantially limit the efficiency of standard InGaN/GaN LED structures. We rather discuss a supplemental Auger-like non-radiative path for carrier recombination that becomes dominant at quantum-well carrier densities typical for LED operation. Additionally, the piezo-field induced reduced overlap of electron and hole wavefunction in standard c-plane grown InGaN quantum wells reduces the radiative recombination rate

Delphi4LED - From measurements to standardized multi-domain compact models of LED : A new European R&D project for predictive and efficient multi-domain modeling and simulation of LEDs at all integration levels along the SSL supply chain

NARCIS (Netherlands)

Bornoff, R.; Hildenbrand, V.; Lungten, S.; Martin, G.; Marty, C.; Poppe, A.; Rencz, M.; Schilders, W.H.A.; Yu, Joan

2016-01-01

There are a few bottlenecks hampering efficient design of products on different integration lepels of the ssL supply chain. one major issue is that data sheet information propided about packaged LEDs is usually insufficient and inconsistent among different LED pendors. Many data such as temperature

Radiation effects in pigtailed GaAs and GaA1As LEDs

International Nuclear Information System (INIS)

Barnes, C.E.

1981-06-01

Permanent and transient radiation effects have been studied in Plessey pigtailed, high radiance GaAs and GaAlAs LEDs using neutron, gamma ray and X-ray sources. The radiation-induced source of degradation in these devices was determined by also examining both bare, unpigtailed LEDs and separate samples of the Corning fibers used as pigtails. No transient effects were observed in the unpigtailed LEDs during either pulsed neutron or X-ray exposure. In contrast, the Corning doped silica fibers exhibited strong transient attenuation following pulsed X-ray bombardment. Permanent neutron damage in these pigtailed LEDs consisted essentially of light output degradation in the LED itself. Permanent gamma ray effects due to a Co-60 irradiation of 1 megarad were restricted to a small increase in attenuation in the fiber. The two primary radiation effects were then transient attenuation in the fiber pigtail and permanent neutron-induced degradation of the LED

An investment-led approach to analysing the hydrogen energy economy in the UK

International Nuclear Information System (INIS)

Houghton, T.; Cruden, A.

2009-01-01

The authors propose an alternative, investment-led approach to analysing the potential for the development of hydrogen energy in the UK. The UK economy is relatively sensitive to movements in world fossil fuels markets since the energy sector contributes at least 5% of UK GDP and represents an asset pool of at least pound 230 billion. Much of the ongoing research to assess possible scenarios for the development of alternatives to existing energy systems, including hydrogen energy, in the UK is built around the cost-optimising MARKAL model. The authors believe that this approach offers an incomplete picture of hydrogen energy deployment since it ignores the mechanisms dictating the flow of commercial capital to the sector and they suggest an alternative model based on the risk-adjusted value proposition. Initial analysis shows that valuation differentials already exist between companies in the fossil fuel, utilities and fuel cell sectors and that this might be exploited to the advantage of investors thus affecting the speed of development in hydrogen energy. It should be noted that the following represents work in progress and the authors intend to publish an extended analysis in due course. (author)

Development of a Topical Resveratrol Formulation for Commercial Applications Using Dendrimer Nanotechnology.

Science.gov (United States)

Pentek, Tyler; Newenhouse, Eric; O'Brien, Brennin; Chauhan, Abhay Singh

2017-01-14

Resveratrol (RSV) is well known for its anti-oxidant and anti-aging properties. However, resveratrol is insoluble in water and has stability issues. Recently, efforts were placed to prepare a resveratrol-based advanced anti-aging topical product but it contains harsh organic solvents and oils that could be harmful to the human body and the environment. Hence, we propose the use of a multifunctional dendrimer to solve the solubility and stability issues of resveratrol. A dendrimer-resveratrol complex was prepared, optimized and tested for solubility enhancement, stability in solution and cream dosage forms. We have also developed a high performance liquid chromatography method to measure the resveratrol within the final product. PAMAM dendrimers increased the solubility and stability of resveratrol in water and semisolid dosage forms. Therefore, this product would be water based 'green' formulation devoid of harsh organic solvents and oils and can be safely applied to the skin. Additionally, we have shown that the dendrimer helped to increase overall RSV loading and skin penetration of resveratrol. The dendrimer-RSV formulation was successfully scaled up towards commercialization. Dendrimer with RSV has led to an innovation in anti-aging cream and solutions that could be commercially marketed. Dendrimer-RSV complex could also be added to other product forms for additional purposes and applications.

36 CFR 1005.6 - Commercial vehicles.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Commercial vehicles. 1005.6 Section 1005.6 Parks, Forests, and Public Property PRESIDIO TRUST COMMERCIAL AND PRIVATE OPERATIONS § 1005.6 Commercial vehicles. (a) The term “Commercial vehicle” as used in this section shall include, but...

50 CFR 404.10 - Commercial fishing.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Commercial fishing. 404.10 Section 404.10... MARINE NATIONAL MONUMENT § 404.10 Commercial fishing. (a) Lobster fishing. Any commercial lobster fishing... species. (1) Notwithstanding the prohibitions in § 404.7(a) and (h), commercial fishing for bottomfish and...

Commercializing a U.S. piezoceramic linear motor

Science.gov (United States)

Diehl, Rick W.

2000-06-01

A small low-cost piezoceramic linear motor has been developed in the US and is being commercialized by EDO Corporation, working with a leading motion control OEM and with a prominent US corporate research laboratory. First generation motor design has emphasized high displacement at up to 200mm per second velocity with 3.5 Newtons force with high resolution, short time constant and a 15 volt power supply at a cost of less than 100 dollars. Motor dimensions of 30 by 50 by 4 mm allow broad configuration choices, al hidden within the motion control slide. The EDO approach was to build on its core competence in high reliability electroceramic material engineering and production, and to use a strategy of back-integrating, or outsourcing of recent advances outside Edo in piezoceramics, while forward- integrating into specific emerging applications known intimately by the OEM in the market. The strategy provided design focus that has led to a cost-effective advance in 'solid-state actuation and control'. This is considered a classic case of successful industrial integration of an enabling technology across organizations in order to access the needed mix of technology for development of an innovative and competitive solution.

Commercialization in Innovation Management

DEFF Research Database (Denmark)

Sløk-Madsen, Stefan Kirkegaard; Ritter, Thomas; Sornn-Friese, Henrik

For any firm, the ultimate purpose of new product development is the commercialization of the new offerings. Despite its regular use in the product innovation and general management science literature, commercialization is only loosely defined and applied. This lack of conceptual clarity about...... the processes at the interface between product development and customer application is noteworthy as it hinders the theoretical development of the field. In this paper, we explore how research has advanced our understanding of commercialization in product innovation over a 30 year period by mapping different...

Daylight integrated illumination control of LED systems based on enhanced presence sensing

NARCIS (Netherlands)

Pandharipande, A.; Caicedo Fernandez, D.R.

2011-01-01

Light emitting diodes (LEDs) are considered to become the dominant source of illumination in the future, offering long life times, energy efficiency and flexible tunability. The flexibility of adapting LED parameters offers multiple degrees of freedom in designing LED based lighting systems. In this

Construction of an array of LEDs coupled to a concentrator for phototherapy

Science.gov (United States)

Almeida, Joana; Liang, Dawei

2011-07-01

The use of LED devices for phototherapy has been expanding in the last decade. This technology provides a safer emission spectrum in large target tissue areas when compared to laser emissions. For enhancing the phototherapeutic effects of red light emitted by LEDs, a simple optical concentrator capable of efficient light concentration and homogenization was developed. The LEDs wavelength of 660 nm is coincident with an absorption peak of the mitochondrial photoreceptor molecule cytochrome c oxidase. The prototype was optimized by non-sequential ray-tracing software ZEMAX, attaining both excellent light uniformity and 50mW/cm2 irradiance at the concentrator output end. Heat emanated from the LEDs source is effectively dissipated by the side walls of the concentrator, ensuring a nearly constant temperature environment for tissue treatment. The prototype was tested on cutaneous hyperpigmented marks caused by cupping in two healthy volunteers. Marks were irradiated by LEDs radiations with or without the use of concentrator respectively. Equal exposure durations and light fluences were tested. The use of the concentrator-coupled LEDs source revealed an activation of blood movement immediately after LEDs exposure, an effect not attainable by the LEDs source without the concentrator even at extended exposure time. Promising futures for the treatment of inflammation, tissue repair and skin rejuvenation could be expected by adopting this simple technique.

The Price-Anderson Act: A Linchpin in the Development of Commercial Nuclear Power in the United States

International Nuclear Information System (INIS)

Quattrocchi, J. L.

2006-01-01

The dawn of the atomic age brought with it both the hope of great benefit and the fear of great disaster. By the mid-1950's, the United States recognized that it was in the national interest to promote commercial development of nuclear energy in medicine and industry, particularly in the generation of electric power. The uncertainties of the technology and the potential for severe accidents were clear obstacles to commercial development. Exposure to potentially serious uninsured liabilities inhibited the private sector. These impediments led Congress to enact the Price-Anderson Act in 1957. Its three-fold purpose was to encourage private development of nuclear power, establish a framework for handling liability claims and provide a ready source of funds to compensate accident victims. The law was originally enacted for ten years but has now been extended four times. The major provisions of the Act and its importance to the public and to insurers are described in this paper.(author)

Analyzing Thermal Module Developments and Trends in High-Power LED

Directory of Open Access Journals (Sweden)

Jung-Chang Wang

2014-01-01

Full Text Available The solid-state light emitting diode (SSLED has been verified as consumer-electronic products and attracts attention to indoor and outdoor lighting lamp, which has a great benefit in saving energy and environmental protection. However, LED junction temperature will influence the luminous efficiency, spectral color, life cycle, and stability. This study utilizes thermal performance experiments with the illumination-analysis method and window program (vapour chamber thermal module, VCTM V1.0 to investigate and analyze the high-power LED (Hi-LED lighting thermal module, in order to achieve the best solution of the fin parameters under the natural convection. The computing core of the VCTM program employs the theoretical thermal resistance analytical approach with iterative convergence stated in this study to obtain a numerical solution. Results showed that the best geometry of thermal module is 4.4 mm fin thickness, 9.4 mm fin pitch, and 37 mm fin height with the LED junction temperature of 58.8°C. And the experimental thermal resistances are in good agreement with the theoretical thermal resistances; calculating error between measured data and simulation results is no more than ±7%. Thus, the Hi-LED illumination lamp has high life cycle and reliability.

36 CFR 272.4 - Commercial use.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Commercial use. 272.4 Section... OWLâ SYMBOL § 272.4 Commercial use. (a) General. The Chief may authorize the Commercial manufacture... charge, royalty charge, or payment in kind which is reasonably related to the commercial value has been...

Automated system for the determination of patterns of high-intensity LEDs

International Nuclear Information System (INIS)

Baly, L.; Bolaño, L.; Arteche, R.; Broco, Y.; Quesada, I.; Rodríguez, E.

2008-01-01

Determination of high-intensity LEDs lighting patterns is an important step for the simulation and planning of arrays of these devices configurations. Currently there are systems based on CCD cameras able to efficiently solve this problem, however the high cost of these is a limiting factor for use. Another limitation of CCD cameras, is that they are designed for light levels much lower than those produced by a high-intensity LED. In this paper we present an automated system for the determination of the intensity of LEDs based on the scan point to point patterns. The results of the analysis of a type of LED based on arrays of bars with built-in optical system is presented.

Feasibility of LED-Assisted CMOS Camera: Contrast Estimation for Laser Tattoo Treatment

Directory of Open Access Journals (Sweden)

Ngot Thi Pham

2018-04-01

Full Text Available Understanding the residual tattoo ink in skin after laser treatment is often critical for achieving good clinical outcomes. The current study aims to investigate the feasibility of a light-emitting diode (LED-assisted CMOS camera to estimate the relative variations in tattoo contrast after the laser treatment. Asian mice were tattooed using two color inks (black and red. The LED illumination was a separate process from the laser tattoo treatment. Images of the ink tattoos in skin were acquired under the irradiation of three different LED colors (red, green, and blue for pre- and post-treatment. The degree of contrast variation due to the treatment was calculated and compared with the residual tattoo distribution in the skin. The black tattoo demonstrated that the contrast consistently decreased after the laser treatment for all LED colors. However, the red tattoo showed that the red LED yielded an insignificant contrast whereas the green and blue LEDs induced a 30% (p < 0.001 and 26% (p < 0.01 contrast reduction between the treatment conditions, respectively. The proposed LED-assisted CMOS camera can estimate the relative variations in the image contrast before and after the laser tattoo treatment.

Industry's Commercial Initiatives on ISS

Science.gov (United States)

Shields, C. E.; Kessler, C.; Lavitola, M. S.

2002-01-01

For more than ten years, private industry has worked to develop a commercial human space market and to create a sustainable ISS commercial utilization customer base. Before ISS assembly was underway - and long before NASA and the international space agencies began to craft ISS commercial business terms and conditions - industry planted and nurtured the seeds of interest in exploiting human space utilization for commerce. These early initiatives have yielded the impetus and framework for industry approaches to ISS commercial utilization today and for NASA's and the International Partners' planned accommodation of private sector interests and desires on the ISS. This paper chronicles major industry initiatives for commercial ISS utilization, emphasizing successful marketing and business approaches and why these approaches have a higher likelihood of success than others. It provides an overview of individual companies' initiatives, as well as collaborative efforts that cross company lines and country borders; and it assesses the relative success of each. Rather than emphasize negative issues and barriers, this paper characterizes and prioritizes actionable success factors for industry and government to make ISS commercial utilization a sustainable reality.

Baby-Led Introduction to SolidS (BLISS) study: a randomised controlled trial of a baby-led approach to complementary feeding.

Science.gov (United States)

Daniels, Lisa; Heath, Anne-Louise M; Williams, Sheila M; Cameron, Sonya L; Fleming, Elizabeth A; Taylor, Barry J; Wheeler, Ben J; Gibson, Rosalind S; Taylor, Rachael W

2015-11-12

In 2002, the World Health Organization recommended that the age for starting complementary feeding should be changed from 4 to 6 months of age to 6 months. Although this change in age has generated substantial debate, surprisingly little attention has been paid to whether advice on how to introduce complementary foods should also be changed. It has been proposed that by 6 months of age most infants will have developed sufficient motor skills to be able to feed themselves rather than needing to be spoon-fed by an adult. This has the potential to predispose infants to better growth by fostering better energy self-regulation, however no randomised controlled trials have been conducted to determine the benefits and risks of such a "baby-led" approach to complementary feeding. This is of particular interest given the widespread use of "Baby-Led Weaning" by parents internationally. The Baby-Led Introduction to SolidS (BLISS) study aims to assess the efficacy and acceptability of a modified version of Baby-Led Weaning that has been altered to address potential concerns with iron status, choking and growth faltering. The BLISS study will recruit 200 families from Dunedin, New Zealand, who book into the region's only maternity hospital. Parents will be randomised into an intervention (BLISS) or control group for a 12-month intervention with further follow-up at 24 months of age. Both groups will receive the standard Well Child care provided to all parents in New Zealand. The intervention group will receive additional parent contacts (n = 8) for support and education on BLISS from before birth to 12 months of age. Outcomes of interest include body mass index at 12 months of age (primary outcome), energy self-regulation, iron and zinc intake and status, diet quality, choking, growth faltering and acceptability to parents. This study is expected to provide insight into the feasibility of a baby-led approach to complementary feeding and the extent to which this method of

Integrated Automotive High-Power LED-Lighting Systems in 3D-MID Technology

NARCIS (Netherlands)

Thomas, W.

2014-01-01

The growing energy consumption of lighting as well as rising luminous efficacies and -fluxes of high-power Light Emitting Diodes (LEDs) have contributed to the widespread use of LEDs in modern lighting systems. One of the most prominent users of the LED-technology is automotive (exterior) lighting.

A novel dimmable LED driver with soft-start and UVLO circuits

International Nuclear Information System (INIS)

Jiang Jinguang; Tan Gaojian; Zhou Xifeng; Zhang Zeyu

2015-01-01

A fully integrated LED driver based on a current mode PWM boost DC—DC converter with constant output current is proposed. In order to suppress the inrush of current and the overshoot voltage at the start up state, a soft-start circuit is adopted. Additionally, to adjust the LED brightness without color variation over the full dimming range and achieve high efficiency, a PWM dimming circuit is presented. Furthermore, to keep the loop stability of the LED driver, an internal slope compensation network is designed to avoid the sub-harmonic oscillation when the duty cycle exceeds 50%. Finally, a UVLO circuit is adopted to improve the reliability of the LED driver against the input voltage changing. The LED driver has been fabricated with a standard 0.5 μm CMOS process, and only occupies 1.21 × 0.76 mm 2 . Experimental results show that the brightness of the LED can be adjusted by an off-chip PWM signal with a wide adjusting range. The inductor current and output current increase smoothly over the whole load range. The chip is in the UVLO condition when the input voltage is below 2.18 V and has achieved about 137 μs typical start-up time. (semiconductor integrated circuits)

Transition of Japanese commercial space: What has been lost from the commercial space?

Directory of Open Access Journals (Sweden)

Fujioka Tatsuma

2016-12-01

Full Text Available This paper compares the types of two commercial spaces in modern Japan, shopping mall and “traditional” shopping district called Shotengai, from the viewpoint of commercial space as the third space in the city. Particularly in the discourse of commercial spaces in Japan, "shopping district" has been portrayed tied to nostalgia. Therefore, the transition of commercial space is always accompanied by a discourse of the" Lost." However, there is no unified opinion about what's been lost in the process of this transition in fact. In this paper, we extract the social category by considering focus on discourse for both places. As a specific object I use to target the research papers and journal articles in Japan. Because these documents are discussed by distinct main thesis and based on specific data, I adopt these materials. After extraction of social category, through the comparison of the two discourses, I reveal what kind of nature is the "Lost" at the commercial spaces as the third place in the city. I also discuss how this change is related the changes in Japanese social relationship and community.

An Overview of Clinical and Commercial Impact of Drug Delivery Systems

Science.gov (United States)

Anselmo, Aaron C.; Mitragotri, Samir

2014-01-01

Drug delivery systems are widely researched and developed to improve the delivery of pharmaceutical compounds and molecules. The last few decades have seen a marked growth of the field fueled by increased number of researchers, research funding, venture capital and the number of start-ups. Collectively, the growth has led to novel systems that make use of micro/nano-particles, transdermal patches, inhalers, drug reservoir implants and antibody-drug conjugates. While the increased research activity is clearly an indication of proliferation of the field, clinical and commercial translation of early-stage research ideas is critically important for future growth and interest in the field. Here, we will highlight some of the examples of novel drug delivery systems that have undergone such translation. Specifically, we will discuss the developments, advantages, limitations and lessons learned from: (i) microparticle-based depot formulations, (ii) nanoparticle-based cancer drugs, (iii) transdermal systems, (iv) oral drug delivery systems, (v) pulmonary drug delivery, (vi) implants and (vii) antibody-drug conjugates. These systems have impacted treatment of many prevalent diseases including diabetes, cancer and cardiovascular diseases, among others. At the same time, these systems are integral and enabling components of products that collectively generate annual revenues exceeding US $100 billion. These examples provide strong evidence of the clinical and commercial impact of drug delivery systems. PMID:24747160

Radon investigations - Soil and commercial projects

International Nuclear Information System (INIS)

Goodwin, R.W.

1987-01-01

The liability issues of radon exposure have prompted potential purchasers of vacant land for commercial/industrial development, and commercial landlords, renting large commercial buildings, to determine the radon gas levels at such sites. This paper deals with both pre-construction sites subject to freezing conditions and to large commercial structures. A correlation of radon gas levels within a commercial building and a sister pre-construction site confirms the validity of using activated charcoal canisters as a cost effective means to combating radon in large structures

EVALUATION OF ADOPTION OF LED LIGHTING TECHNOLOGY IN MALAYSIA

OpenAIRE

Khorasanizadeh, Hasti

2017-01-01

Electrical energy consumption in Malaysia is rapidly increasing with illumination being the second largest contributor to this increment. Light Emitting Diode (LED) could be a viable option to reduce the illumination based energy consumption. LEDs are energy efficient and easier to recycle compared to traditional lighting sources such as incandescent and fluorescent lamps. They also have longer life time and lower failure rate. In this thesis, the feasibility of replacing...

A Comparison of Midwife-Led and Medical-Led Models of Care and Their Relationship to Adverse Fetal and Neonatal Outcomes: A Retrospective Cohort Study in New Zealand.

Directory of Open Access Journals (Sweden)

Ellie Wernham

2016-09-01

Full Text Available Internationally, a typical model of maternity care is a medically led system with varying levels of midwifery input. New Zealand has a midwife-led model of care, and there are movements in other countries to adopt such a system. There is a paucity of systemic evaluation that formally investigates safety-related outcomes in relationship to midwife-led care within an entire maternity service. The main objective of this study was to compare major adverse perinatal outcomes between midwife-led and medical-led maternity care in New Zealand.This was a population-based retrospective cohort study. Participants were mother/baby pairs for all 244,047 singleton, term deliveries occurring between 1 January 2008 and 31 December 2012 in New Zealand in which no major fetal, neonatal, chromosomal or metabolic abnormality was identified and the mother was first registered with a midwife, obstetrician, or general practitioner as lead maternity carer. Main outcome measures were low Apgar score at five min, intrauterine hypoxia, birth-related asphyxia, neonatal encephalopathy, small for gestational age (as a negative control, and mortality outcomes (perinatal related mortality, stillbirth, and neonatal mortality. Logistic regression models were fitted, with crude and adjusted odds ratios (ORs generated for each outcome for midwife-led versus medical-led care (based on lead maternity carer at first registration with 95% confidence intervals. Fully adjusted models included age, ethnicity, deprivation, trimester of registration, parity, smoking, body mass index (BMI, and pre-existing diabetes and/or hypertension in the model. Of the 244,047 pregnancies included in the study, 223,385 (91.5% were first registered with a midwife lead maternity carer, and 20,662 (8.5% with a medical lead maternity carer. Adjusted ORs showed that medical-led births were associated with lower odds of an Apgar score of less than seven at 5 min (OR 0.52; 95% confidence interval 0

Evaporative Gasoline Emissions and Asthma Symptoms

Science.gov (United States)

Gordian, Mary Ellen; Stewart, Alistair W; Morris, Stephen S

2010-01-01

Attached garages are known to be associated with indoor air volatile organic compounds (VOCs). This study looked at indoor exposure to VOCs presumably from evaporative emissions of gasoline. Alaskan gasoline contains 5% benzene making benzene a marker for gasoline exposure. A survey of randomly chosen houses with attached garages was done in Anchorage Alaska to determine the exposure and assess respiratory health. Householders were asked to complete a health survey for each person and a household survey. They monitored indoor air in their primary living space for benzene, toluene, ethylbenzene and xylenes for one week using passive organic vapor monitoring badges. Benzene levels in homes ranged from undetectable to 58 parts per billion. The median benzene level in 509 homes tested was 2.96 ppb. Elevated benzene levels in the home were strongly associated with small engines and gasoline stored in the garage. High concentrations of benzene in gasoline increase indoor air levels of benzene in residences with attached garages exposing people to benzene at levels above ATSDR’s minimal risk level. Residents reported more severe symptoms of asthma in the homes with high gasoline exposure (16%) where benzene levels exceeded the 9 ppb. PMID:20948946

Colorimetric characterization of LED luminaires

International Nuclear Information System (INIS)

Costa, C L M; Vieira, R R; Pereira, R C; Silva, P V M; Oliveira, I A A; Sardinha, A S; Viana, D D; Barbosa, A H; Souza, L P; Alvarenga, A D

2015-01-01

The Optical Metrology Division of Inmetro – National Institute of Metrology, Quality and Technology has recently started the colorimetric characterization of lamps by implementing Correlated Color Temperature (CCT) and Color Rendering Index (CRI) measurements of incandescent lamps, followed by the CFL, and LED lamps and luminaires. Here we present the results for the verification of the color characterization of samples of SSL luminaires for public as well as indoor illumination that are sold in Brazil

Phenotypic and metabolic traits of commercial Saccharomyces cerevisiae yeasts.

Science.gov (United States)

Barbosa, Catarina; Lage, Patrícia; Vilela, Alice; Mendes-Faia, Arlete; Mendes-Ferreira, Ana

2014-01-01

Currently, pursuing yeast strains that display both a high potential fitness for alcoholic fermentation and a favorable impact on quality is a major goal in the alcoholic beverage industry. This considerable industrial interest has led to many studies characterizing the phenotypic and metabolic traits of commercial yeast populations. In this study, 20 Saccharomyces cerevisiae strains from different geographical origins exhibited high phenotypic diversity when their response to nine biotechnologically relevant conditions was examined. Next, the fermentation fitness and metabolic traits of eight selected strains with a unique phenotypic profile were evaluated in a high-sugar synthetic medium under two nitrogen regimes. Although the strains exhibited significant differences in nitrogen requirements and utilization rates, a direct relationship between nitrogen consumption, specific growth rate, cell biomass, cell viability, acetic acid and glycerol formation was only observed under high-nitrogen conditions. In contrast, the strains produced more succinic acid under the low-nitrogen regime, and a direct relationship with the final cell biomass was established. Glucose and fructose utilization patterns depended on both yeast strain and nitrogen availability. For low-nitrogen fermentation, three strains did not fully degrade the fructose. This study validates phenotypic and metabolic diversity among commercial wine yeasts and contributes new findings on the relationship between nitrogen availability, yeast cell growth and sugar utilization. We suggest that measuring nitrogen during the stationary growth phase is important because yeast cells fermentative activity is not exclusively related to population size, as previously assumed, but it is also related to the quantity of nitrogen consumed during this growth phase.

Uniform illumination rendering using an array of LEDs: a signal processing perspective

OpenAIRE

Yang, Hongming; Bergmans, J.W.M.; Schenk, T.C.W.; Linnartz, J.P.M.G.; Rietman, R.

2009-01-01

An array of a large number of LEDs will be widely used in future indoor illumination systems. In this paper, we investigate the problem of rendering uniform illumination by a regular LED array on the ceiling of a room. We first present two general results on the scaling property of the basic illumination pattern, i.e., the light pattern of a single LED, and the setting of LED illumination levels, respectively. Thereafter, we propose to use the relative mean squared error as the cost function ...

Semi-commercialization of PVP-carrageenan hydrogel

International Nuclear Information System (INIS)

Relleve, Lorna S.; Abad, Lucille V.; Aranilla, Charito T.; Dela Rosa, A.M.

2008-01-01

The Philippine Nuclear Research Institute (PNRI) has developed the PVP-Carrageenan hydrogel wound dressing by radiation processing. The PVP-Carrageenan hydrogel has undergone clinical testing for burn and bedsores. It has already a pending patent application (No. 1-2000-02471) at the Philippine Patent Office. The techno-economic feasibility study has also been completed. In order to commercialize this product, a project on semi-commercialization in partnership with the investor was proposed to Technology Incubation for Commercialization (TECHNICOM), a technology transfer program of the Department of Science and Technology (DOST). TECHNICOM was established in 2003 under the National Science and Technology Plan (2002-2020) as a strategic technology transfer program. The program aims to identify key technological breakthroughs especially those generated by R and D institutes. It can intervene through the following: technology assessment/commercial prototype development; business plan/feasibility study preparation; intellectual property rights protection; technology valuation negotiation and licensing; semi-commercial production assistance and training/consultancy services. High technology applications with commercial potentials are given priority. Under semi-commercialization stage, government funds will be provided to match private sector investment in the commercial application of a particular technology innovation. This will lessen the risk of commercialization and ensure commitment from the investors. Commercial success in the shortest time is ensured since scientist can then work closely with the private sector at the production floor while testing the gaps in the technology. (author)

Assessment of community led total sanitation uptake in rural Kenya ...

African Journals Online (AJOL)

Background: Community Led Total Sanitation (CLTS) is an innovative community led drive to set up pit latrines in rural Kenya with an aim of promoting sustainable sanitation through behaviour change. It's a behaviour change approach based on social capital that triggers households to build pit latrines without subsidy.

Luminous flux and colour maintenance investigation of integrated LED lamps

DEFF Research Database (Denmark)

Corell, Dennis Dan; Thorseth, Anders; Dam-Hansen, Carsten

2014-01-01

This article will present an investigation of the luminous flux and colour maintenance of white LED based retrofit lamps. The study includes 23 different types of integrated LED lamps, covering 18 directional and 5 non-directional. Luminous flux and colour data for operation up to 20000 h has been...

Campylobacter jejuni in commercial eggs.

Science.gov (United States)

Fonseca, Belchiolina Beatriz; Beletti, Marcelo Emílio; de Melo, Roberta Torres; Mendonça, Eliane Pereira; Coelho, Letícia Ríspoli; Nalevaiko, Priscila Christen; Rossi, Daise Aparecida

2014-01-01

This study evaluated the ability of Campylobacter jejuni to penetrate through the pores of the shells of commercial eggs and colonize the interior of these eggs, which may become a risk factor for human infection. Furthermore, this study assessed the survival and viability of the bacteria in commercial eggs. The eggs were placed in contact with wood shavings infected with C. jejuni to check the passage of the bacteria. In parallel, the bacteria were inoculated directly into the air chamber to assess the viability in the egg yolk. To determine whether the albumen and egg fertility interferes with the entry and survival of bacteria, we used varying concentrations of albumen and SPF and commercial eggs. C. jejuni was recovered in SPF eggs (fertile) after three hours in contact with contaminated wood shavings but not in infertile commercial eggs. The colonies isolated in the SPF eggs were identified by multiplex PCR and the similarity between strains verified by RAPD-PCR. The bacteria grew in different concentrations of albumen in commercial and SPF eggs. We did not find C. jejuni in commercial eggs inoculated directly into the air chamber, but the bacteria were viable during all periods tested in the wood shavings. This study shows that consumption of commercial eggs infected with C. jejuni does not represent a potential risk to human health.